Process for preparing copolymers and blend compositions containing the same

ABSTRACT

A process for the preparation of blends including an ethylene copolymer by copolymerizing ethylene and at least one comonomer selected from a compound represented by the formula H 2 C═CHR wherein R is an alkyl group or an aryl group, and a diene, in the presence of a solid catalyst system comprising a support, a transition metal compound and an activator capable of converting the transition metal compound into a catalytically active transition metal complex.

The present application is a divisional of U.S. application Ser. No.09/955,257, filed Sep. 18, 2001, now abandoned, which is a continuationof U.S. application Ser. No. 09/180,788, filed Nov. 16, 1998, nowabandoned, which is a national phase entry of International ApplicationNo. PCT/US97/08466, filed May 16, 1997, which claims priority toJapanese Patent Application No. H08-148392, filed May 17, 1996; each ofwhich is incorporated herein in its entirety by reference.

The present invention relates to an ethylene copolymer and a method forproducing the same. More particularly, the present invention isconcerned with an ethylene copolymer comprising a copolymer of ethylenewith at least one comonomer selected from (a) the group comprisingcompounds represented by the formula H₂C═CHR wherein R represents aC₁–C₂₀ linear, branched or cyclic alkyl group or a C₆–C₂₀ aryl group,and (b) a C₄–C₂₀ linear, branched or cyclic diene; and the copolymerhaving, a specific density, and having not only a specific molecularweight distribution characteristic, but also a specific comonomercontent distribution characteristic.

The present invention also relates to blend compositions comprising saidnovel ethylene copolymer and:

a) a second ethylene copolymer of the present invention of differentmolecular weight or density; or

b) a homogeneous narrow composition distribution ethylene interpolymer;

c) a heterogeneous broad composition distribution ethylene interpolymeror

d) a homopolymer (prepared by a catalyst component other than that usedto prepare the ethylene copolymer of the present invention); or

e) a combination of any two or more of a), b) c) or d).

The present invention is also concerned with a novel method forproducing the blend compositions comprising the ethylene copolymer ofthe present invention.

The ethylene copolymer of the present invention has great advantageswhich have not been provided by conventional ethylene copolymers, thatis , it contains no impurities such as a wax, a gel. In addition boththe ethylene copolymer and blend compositions therefrom of the presentinvention also have excellent properties, such as high impact strengthand excellent environmental stress cracking resistance, such that theycan be advantageously used for the production of laminate films,blow-molded articles, pipes, coating materials for electric transmissioncables.

Ethylene copolymers are widely used in various application fields, suchas the production of films, blow-molded products, pipes and coatingmaterials for electric transmission cables. With respect to any of theseapplications, it is required that an ethylene copolymer not only containfew impurities, such as wax, gels, but also exhibit excellentproperties, such as high impact strength and high environmental stresscracking resistance (hereinafter, frequently referred to as “ESCRproperties”). However attempts to vary the molecular structure of apolymer to cause an improvement in one such property often results in aloss of performance in another. For instance polymers exhibiting highstiffness and heat resistance should have high crystallinity and lowcomonomer content, however this can cause a loss of toughness, ESCR, lowoptical properties and poor heat seal performance. Similarly forimproved polymer processability (low extrusion amp and back pressure andno melt fracture) it is desirable to use polymers having a low molecularweight, and a broad molecular weight distribution with significantlevels of long chain branching. However broad molecular weightdistribution, especially at low polymer molecular weight, often causeswax buildup on the die, smoke generation on the extruder, and taste andodor problems in the resulting fabricated articles.

It is known that improvement in impact and environmental stress crackresistance of an ethylene copolymer, can be achieved by decreasing thecomonomer content of the low molecular weight fraction of the ethylenecopolymer to a level as low as possible while increasing the comonomercontent of the high molecular weight fraction of the ethylene copolymerto a level as high as possible. It has also been demonstrated (as forexample by Zhou et al, Polymer, Vol. 24, p. 2520 (1993)) that largestrain properties such as toughness, tear, impact and ESCR can also beimproved by the presence of “the molecules” in the resin. High molecularweight molecules with the highest comonomer content (that is the highestdegree of short chain branching) are responsible for the formation ofmost of the tie molecules upon crystallization.

Thus it would be highly desirable for a copolymer to have a specificcomonomer content distribution characteristic, wherein, in one aspect,the lower the molecular weight of a copolymer fraction in a molecularweight distribution of a said copolymer, the lower the comonomer contentof the copolymer fraction; and, in the other aspect, the higher themolecular weight of a fraction of said copolymer, the higher thecomonomer content of the copolymer fraction.

However, in ethylene copolymers which are produced using a conventionalZiegler-Natta catalyst, it is likely that the lower the molecular weightof a copolymer fraction, the higher its comonomer content. Thus, suchconventional ethylene copolymers have a comonomer content distributionwhich is completely contrary to the above-mentioned desired comonomercontent distribution. Therefore, such conventional ethylene copolymersare at a disadvantage with respect to desirable properties, such asimproved impact strength and ESCR.

Attempts to maximize toughness, modulus, impact strength and ESCR ofethylene copolymers has resulted in the preparation and use of blendcompositions made out of two or more ethylene copolymer components ofdiffering molecular structures. In addition to separately blendingselected individual polymer components after their manufacture andisolation (so called “off-line” blending), such compositions can also beprepared by a method in which a copolymerization of ethylene with acomonomer is conducted by a multi-stage polymerization, using aplurality of different polymerization reactors, capable of providingdifferent copolymerization conditions. This allows so called “inreactor” or “in process” production of ethylene copolymers comprising amixture of a low molecular weight copolymer component, having a lowcomonomer content, and a high molecular weight copolymer componenthaving a high comonomer content.

Such blend compositions containing solely Ziegler catalyst products aredescribed in a number of patents. For example, Nelson (U.S. Pat. No.3,280,220, Phillips Petroleum) teaches that a blend of an ethylenehomopolymer of low molecular weight (formed in a solution process) andan ethylene/butene-1 copolymer of high molecular weight (formed in aparticle forming process) provides higher ESCR and is more advantageousfor containers and pipe than other such blends.

Hoblitt et al. (U.S. Pat. No. 3,660,530, the Dow Chemical Company)teaches a method where part of a homopolymer produced after a firstreaction step is subjected to 1-butene. The still active catalyst thenproduces a block copolymer of polyethylene and polymerized butene-1.Both components are then admixed. The resultant blend has improved ESCRproperties.

Fukushima et al, (U.S. Pat. No. 4,438,238) disclose blends consisting ofcomponents with densities between 0.910 and 0.940 g/cm³ and broadmolecular weight distributions with the polymers having substantially nolong chain branches. These blends were found to have processabilitysimilar to that of high pressure polyethylene.

Bailey et al. (U.S. Pat. No. 4,547,551) teach that ethylene polymerblends of a high molecular weight ethylene polymer, preferably anethylene/α-olefin copolymer, and a low molecular weight ethylenepolymer, preferably an ethylene homopolymer, both preferentially havinga narrow molecular weight distribution and low levels of long chainbranching, exhibit excellent film properties and a better balance ofstiffness and impact and ESCR, than expected for polyethylene ofcomparable density and flow.

Morimoto et al. (U.S. Pat. Nos. 5,189,106, and 5,260,384) discloseblends consisting of a high molecular weight copolymer in combinationwith a low molecular weight homopolymer having good processability andexcellent low temperature mechanical properties.

Boehm et al., (Advanced Materials 4 (1992) no 3, p 237), disclose thecascade polymerization process in which the comonomer is introduced inthe high molecular weight fraction of the polymer resulting in a largeramount of comonomer being present at the same overall density. This inturn results in a polymer composition having improved rigidity-lifetime(failure time) compared to conventional unimodal copolymers. Severalpatents have also appeared teaching the process to produce suchmaterials in such cascade processes including EP 0 022 376 (Morita etal).

Unexamined Japanese Patent Application Laid-Open Specification Nos.61-221245 and 61-57638, disclose attempts to increase the comonomercontent of high molecular weight copolymer fractions by a method inwhich a low molecular weight polymer having a low comonomer content anda high molecular weight polymer having a high comonomer content areseparately produced and blended by means of a kneader, or a method inwhich a copolymerization of ethylene with a comonomer is conducted bymulti-stage polymerization, thereby producing an ethylene copolymercomprising a mixture of a low molecular weight polymer component havinga low comonomer content and a high molecular weight polymer componenthaving a high comonomer content.

Finally, Sakurai et al (U.S. Pat. No. 4,230,831) disclose that it isbeneficial to mix low density polyethylene with various blendcompositions to improve polymer die swell or melt tension.

In single component ethylene copolymers produced by employing a Zieglercatalyst, some improvement is achieved with respect to impact resistanceand ESCR properties. Such ethylene copolymers, however, inherentlyexhibit not only a broad molecular weight distribution but also a broadtail on both the low and high molecular weight side of the molecularweight distribution. The presence of the low molecular weight materialcan disadvantageously lead to wax formation. On the other hand, the highmolecular weight material can disadvantageously lead to gel formation.

In addition, blend compositions which are a mixture of such ethylenecopolymers produced by a Ziegler catalyst, may comprise componentcopolymers which are completely different from each other in properties,that is, a low molecular weight polymer component having a low comonomercontent and a high molecular weight polymer component having a highcomonomer content. This can lead to the component polymers undergoingphase separation such that the dispersion of the component polymersbecomes non-uniform, and thus not only does the ethylene copolymerbecome non-uniform in properties but also gel formation occurs.

As an alternative to the use of Ziegler-Natta catalysts, the use ofmetallocene catalysts has recently been proposed (DE 31271332) andcommercialized. As disclosed in, for example, Worldwide MetalloceneConference (Metcon) '93 May 26–28, Houston Tex., p. 171–172 and p.235–244 (1993) and Proceedings of 5th International Business Forum onSpecialty Polyolefins '95. September 20–22. Houston Tex., p. 341–352(1995), an ethylene copolymer produced using such a metaliocene catalysthas characteristics such that both a low molecular weight fraction and ahigh molecular weight fraction have approximately the same comonomercontent, and that the comonomer content distribution is almost uniformacross the molecular weight distribution of the copolymer. That is, anethylene copolymer produced using a metallocene catalyst has a moreuniform comonomer content distribution than that of an ethylenecopolymer produced using a Ziegler-Natta catalyst. On the other hand,however, ethylene copolymers produced using a metallocene catalyst arestill unsatisfactory with respect to desired improvements in impactresistance and ESCR properties of products of such copolymers.

Again, as was the case with Ziegler catalyst products, attempts toimprove properties such as ESCR and impact resistance of products ofmetallocene catalysts have included their incorporation into blendcompositions. A number of techniques have been proposed to prepare suchblends, including a method in which two or more different ethylenecopolymers having different comonomer contents are separately producedand blended by means of a kneader or a method in which an ethylenecopolymer comprised of a mixtures of two or more different ethylenecopolymer components having different comonomer contents is produced bymulti-stage polymerization (see, for example, EP 0 447 035). Further, ithas also been proposed to use a method in which a mixture of two or moredifferent types of metallocene catalysts is used to produce an ethylenecopolymer comprised of a mixture of two or more different ethylenecopolymer components having different comonomer contents (see, forexample, U.S. Pat. Nos. 4,937,299 and 4,530,914).

However, an ethylene copolymer produced using a metallocene catalysttypically has a very narrow molecular weight distribution (M_(w)/Mn) ofapproximately 2. Therefore, when two different types of copolymers,namely a low molecular weight copolymer and a high molecular weightcopolymer which are extremely different in molecular weight from eachother, are produced using different metallocene catalysts, therespective amounts of copolymer chains having common molecular weightsis very small in the two different copolymers, so that the compatibilitybetween these two different copolymers is very poor.

In order to solve the above-mentioned problem, a method in which anethylene copolymer produced using a metallocene catalyst is blended withan ethylene copolymer produced using a Ziegler-Natta catalyst has beenproposed, for example, in EP 0 439 964 and EP 0 435 514. Further, amethod in which an ethylene copolymer produced using a metallocenecatalyst is blended with an ethylene copolymer produced by a highpressure polymerization process has been disclosed, for example, inUnexamined Japanese Patent Application Laid-Open Specification Nos.6-207059 and 6-329848.

However there remains a requirement to produce an ethylene copolymerwhich not only contains few impurities such as wax, gels, but also hasexcellent properties, including high impact strength and excellent ESCR.There also remains a requirement to develop an ethylene copolymer whichcontains no impurities such as a wax, a gel while simultaneouslyexhibiting the above-mentioned desired comonomer content distribution,namely, in one aspect, the lower the molecular weight of a copolymerfraction, the lower the comonomer content of the copolymer fraction;and, in the other aspect, the higher the molecular weight of a copolymerfraction, the higher the comonomer content of the copolymer fraction.

There also remains a requirement to produce blend compositionscomprising said ethylene copolymers which also have excellentproperties, such as high impact strength and excellent ESCR properties.Finally there also remains a requirement for producing blendcompositions with good compatibility between the two components andexhibiting improved uniformity and balance in properties while havinglow wax content and low tendency for gel formation.

It has surprisingly been found that such a required ethylene copolymerand blend composition can be produced using the polymers and thespecific polymerization and blending processes of the present invention.

Accordingly, it is one object of the present invention to provide anovel ethylene copolymer which not only contains substantially noimpurities such as a wax, a gel , but also exhibits a comonomer contentdistribution in which the lower the molecular weight of a fraction ofsaid copolymer the lower the comonomer content and the higher themolecular weight of a fraction of said copolymer the higher thecomonomer content.

It is also an object of the present invention to provide novel blendcompositions comprising said ethylene copolymer which exhibit anexcellent balance and uniformity of properties such as high impactstrength and excellent ESCR while also having a low wax content and areduced tendency to gel formation.

The foregoing and other objects, features and advantages of the presentinvention will become apparent to those skilled in the art from thefollowing detailed description and appended claims.

All references herein to elements or metals belonging to a certain Grouprefer to the Periodic Table of the Elements published and copyrighted byCRC Press, Inc., 1989. Also any reference to the Group or Groups shallbe to the Group or Groups as reflected in this Periodic Table of theElements using the IUPAC system for numbering groups.

Any numerical values recited herein include all values from the lowervalue to the upper value in increments of one unit provided that thereis a separation of at least 2 units between any lower value and anyhigher value. As an example, if it is stated that the amount of acomponent or a value of a process variable such as, for example,temperature, pressure, time is, for example, from 1 to 90, preferablyfrom 20 to 80, more preferably from 30 to 70, it is intended that valuessuch as 15 to 85, 22 to 68, 43 to 51, 30 to 32 etc, are expresslyenumerated in this specification. For values which are less than one,one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 as appropriate.These are only examples of what is specifically intended and allpossible combinations of numerical values between the lowest value andthe highest value enumerated are to be considered to be expressly statedin this application in a similar manner.

The term “hydrocarbyl” as employed herein means any aliphatic,cycloaliphatic, aromatic, aryl substituted aliphatic, aryl substitutedcycloaliphatic, aliphatic substituted aromatic, or aliphatic substitutedcycloaliphatic groups and any combination thereof.

The term “hydrocarbyloxy” means a hydrocarbyl group having an oxygenlinkage between it and the carbon atom to which it is attached.

The term “silyl” means a group having a silicon linkage between it andthe carbon atom to which it is attached.

The term “germyl” means a group having a germanium linkage between itand the carbon atom to which it is attached.

The term “substituted cyclopentadienyl” is intended to includering-substituted or polynuclear derivatives of the cyclopentadienylmoiety wherein the substituent is hydrocarbyl, hydrocarbyloxy,hydrocarbylamino, cyano, halo, silyl, germyl, siloxy or mixtures thereotor two such substituents are a hydrocarbylene group, the substituent (ortwo substituents together) having up to 30 non-hydrogen atoms. Specificexamples of substituted cyclopentadienyls include indenyl,tetrahydroindenyl, fluorenyl, and octahydrofluorenyl groups.

The term “Bronsted Acid cation” means a cation which acts as a protondonor.

The term “interpolymer” is used herein to indicate a polymer wherein atleast two different monomers are polymerized to make the interpolymer.This includes copolymers, terpolymers, etc.

The density of the polymer compositions for use in the present inventionwas measured in accordance with ASTM D-792.

The molecular weight of the polymer compositions for use in the presentinvention is conveniently indicated using a melt index measurementaccording to ASTM D-1238, Condition 190° C./2.16 kg (formally known as“Condition (E)” and also known as I₂) was determined, as were conditions190° C./5 kg, 10 kg and 21.6 kg known as I₅, I₁₀, and ₁₂₁ respectively.Melt index is inversely proportional to the molecular weight of thepolymer. Thus, the higher the molecular weight, the lower the meltindex, although the relationship is not linear. Melt flow ratios weretaken from any pair of these values.

Other useful physical property determinations made on the novel polymercompositions described herein include the melt flow ratio (MFR):measured by determining “I₁₀” (according to ASTM D-1238, Condition 190°C./10 kg (formerly known as “Condition (N)”) and dividing the obtainedI₁₀ by the I₂. The ratio of these two melt index terms is the melt flowratio and is designated as I₁₀/I₂. Other melt flow ratios measuredinclude I₂₁.₆/I₅, and I₂₁ ₆/I₂.

The molecular weight (M_(w)) and distribution (M_(w)/M_(n)) of thepolymers of the present invention were determined by gel permeationchromatography (GPC) on a Waters 150C high temperature chromatographicunit equipped with mixed porosity columns, operating at a systemtemperature of 140° C. The solvent was 1,2,4-trichlorobenzene, fromwhich 0.3 percent by weight solutions of the samples were prepared forinjection. The flow rate was 1.0 milliliters/minute and the injectionsize was 100 microliters.

The molecular weight determination was deduced by using narrow molecularweight distribution polystyrene standards (from Polymer Laboratories) inconjunction with their elution volumes. The equivalent polyethylenemolecular weights were determined by using appropriate Mark-Houwinkcoefficients for polyethylene and polystyrene (as described by Williamsand Ward in Journal of Polymer Science, Polymer Letters. Vol. 6, (621)1968) to derive the following equation:M _(polyethylene) =a*(M _(polystyrene))^(b).In this equation, a=0.4316 and b=1.0. Weight average molecular weight,M_(w), and number average molecular weight, M_(n), was calculated in theusual manner according to the following formula:M _(j)=(Σw _(i)(M _(i) ^(j)))^(j);where w_(i) is the weight fraction of the molecules with molecularweight M_(i) eluting from the GPC column in fraction i and j=1 whencalculating M_(w) and j=−1 when calculating M_(n).

The tensile properties of the molded materials were measured inaccordance with ASTM D 638-76. Tensile strength, yield, toughness and 2%secant modulus of the films was measured in accordance with ASTM D-882;PPT tear was measured in accordance with ASTM D-2582.

The modulus of elasticity of the materials was measured in accordancewith ISO 527.

The viscosity number of the materials in decaline was measured inaccordance with ISO 1191.

Haze was measured on a 0.5 mm thick compression molded specimenaccording to ASTM D 1003.

The Double-V notched impact strength of the materials was measured inaccordance with DIN 53753 (1J pendulum).

The impact properties were evaluated in accordance with JIS-K7111.

The critical strain energy release rate G_(c) was measured in the Charpymode, in accordance with the procedure described by E. Plati and J. G.Williams in Polymer Engineering and Science, June, 1975, Volume 15, No6. pp. 470 to 477. For each temperature at least 6 samples are used. Thesample dimensions are 125 mm×10 mm×10 mm. The bars are machined out ofthick compression molded sheets. The procedure used to mold these sheetswas a modification of the procedure outlined in “A compression moldingtechnique for thick sheets of thermoplastics” by M. J. Cawood and G. A.H. Smith in Polymer Testing 1 (1980), 3–7, was used:

Thus the polymer granules or powders were compression molded in a 10 mmthick mold, laterally insulated using Teflon™. They were heated up to160° C. and kept at 6.7 MPa for three minutes followed by three oneminute cycles of exertion and release. Excessive flash was removed. Thematerial was then heated to 180° C. and kept for about 5 minutes at 6.7MPa, which was also exerted and released for 3 cycles of one minuteeach. Finally the melt was solidified under a pressure of 1.7 MPa andslowly cooled overnight by switching of the heating.

The Bending ESCR Test was carried out in 10 wt % of surface-active agentsolution in accordance with JIS-K6760. The testing temperature was 50°C. or 80° C.

The Pennsylvania Notch Test is a slow crack growth test, performedfollowing the procedure described by X. Lu and N. Brown, Polymer Testing11 (1992), pages 309319. The test is conducted at 2.4 MPa and 80° C. Thesample dimensions are 50 mm×25 mm×10 mm and are machined from the samesheet as the G_(c) bars.

Viscosities were measured on an Rheometrics mechanical spectrometer at190° C. in the oscillatory mode.

Comonomer content was measured using infrared spectroscopy on a BeckmanIR2450 Spectrophotometer.

Intrinsic tear was measured on the compression molded sheet using theElmendorf tear (type B) method as described in ASTM D-1922.

The slope of strain hardening is measured by compression molding aplaque from the polymer to be tested. Typically, the plaque is molded atabout 177° C. for 4 minutes under almost no pressure and then pressedfor 3 minutes under a pressure of about 200 psi. The plaque is thenallowed to cool at about 8° C./minute while still under 200 psipressure. The molded plaque has a thickness of about 0.005 inches. Theplaque is then cut into a dogbone shaped test piece using a steel ruledie. The test piece is 0.315 inches wide and 1.063 inches long. Thestart of the curved portion of the dogbone shape begins at 0.315 inchesfrom each end of the sample and gently curves (that is, tapers) to awidth of 0.09 inches. The curve ends at a point 0.118 inches from thestart of the curve such that the interior portion of the dogbone testpiece has a width of 0.09 inches and a length of 0.197 inches.

The tensile properties of the test sample is tested on an InstronTensile Tester at a crosshead speed of 1 inch/minute. The slope ofstrain hardening is calculated from the resulting tensile curve bydrawing a line parallel to the strain hardening region of the resultingstress/strain curve. The strain hardening region occurs after the samplehas pulled its initial load ((that is, stress) usually with little or noelongation during the intial load) and after the sample has gone througha slight drawing stage (usually with little or no increase in load, butwith increasing elongation (that is, strain)). In the strain hardeningregion, the load and the elongation of the sample both continue toincrease. The load increases in the strain hardening region at a muchlower rate than during the intial load region and the elongation alsoincrease, again at a rate lower than that experienced in the drawingregion. The slope of the parallel line in the strain hardening region isthen determined.

The slope of strain hardening coefficient (SHC) is calculated accordingto the following equation:SHC=(slope of strain hardening)*(I ₂)^(0.25)where I₂ melt index in grams/10 minutes.

In one aspect of the present invention, there is provided an ethylenecopolymer comprising a copolymer of ethylene with at least one comonomerselected from the group consisting of a compound represented by theformula H₂C═CHR wherein R is a C₁–C₂₀ linear, branched or cyclic alkylgroup or a C₆–C₂₀ aryl group, and a C₄–C₂₀ linear, branched or cyclicdiene, prepared by a process copolymerizing said ethylene with saidcomonomer by slurry polymerization in the presence of a solid catalystsystem comprising: a support, a transition metal compound, and anactivator capable of converting the transition metal compound into acatalytically active transition metal complex; and wherein said ethylenecopolymer has the following properties (1) to (5):

(1) a density d (g/cm³) of from 0.870 to 0.980;

(2) an M_(w)/Mn of from 2.5 to 10, wherein M_(w) and M, are,respectively, a weight average molecular weight and a number averagemolecular weight, both as measured by gel permeation chromatography(GPC), in addition, the Mw/Mn satisfies the following inequalities;1.25 log M _(w)−2.5≦M _(w) /M _(n)≦3.5 log Mw−11.0;

(3) when, in cross fractionation chromatography (CFC) of the ethylenecopolymer, with respect to extraction at an arbitrary temperature T(°C.) falling within the range of between a first temperature at which amaximum amount of extraction is exhibited and a second temperature whichis 10° C. higher than the first temperature, the relationship betweenthe arbitrary temperature T(° C.) and a point in molecular weight on amolecular weight distribution profile of a copolymer fraction extractedat the arbitrary temperature T(° C.) at which point in molecular weightthe molecular weight distribution profile of the copolymer fractionshows a peak having a maximum intensity is treated by the least squaresmethod to obtain an approximate straight line, the approximate straightline has a gradient within the range defined by the formula (1):−1≦{log Mp(T ¹)−log Mp(T ²)}/(T ¹ −T ²)≦−0.005  (1)wherein:

-   -   T¹ and T² are two different arbitrary extraction temperatures        T(° C.) within the range of between the first temperature and        the second temperature, and Mp(T¹) and Mp(T²) are, respectively,        molecular weights corresponding to T¹ and T² on the approximate        straight line; and

(4) the measurement of the ethylene copolymer by CFC showscharacteristics such that the sum of respective amounts of copolymerfractions extracted at temperatures which are at least 10° C. lower thanthe first temperature as defined above is 8% by weight or less, based onthe total amount of, excluding purge, copolymer fractions extracted attemperatures in the overall range of extraction temperatures in CFC;

(5) within a range in molecular weight of the ethylene copolymer whichis defined by the formula (II):log(Mt)−log(Mc)≦0.5  (II)wherein:

Mt is a point in molecular weight on a molecular weight distributionprofile at which the profile shows a peak having a maximum intensity,and

Mc is an arbitrary point in molecular weight on the molecular weightdistribution profile; and

the molecular weight distribution profile is obtained together with acomonomer content distribution profile by subjecting the ethylenecopolymer to gel permeation chromatography/Fourier transformationinfrared spectroscopy (GPC/FT-IR), wherein

an approximate straight line obtained from the comonomer contentdistribution profile by the least squares method has a gradient withinthe range defined by the formula (III):0.0005≦{C(Mc ¹)−C(Mc ²)}/(log Mc ¹−log Mc ²)≦0.05  (III)wherein:

-   -   Mc¹ and Mc² are two different arbitrary points (Mc) in molecular        weight which satisfy the formula (II), and    -   C(Mc¹) and C(Mc²) are, respectively, comonomer contents        corresponding to Mc¹ and Mc² on the approximate straight line.

The ethylene copolymer of the present invention defined above is a novelethylene copolymer having advantages in that it not only containssubstantially no impurities such as a wax, a gel, but also has excellentproperties, such as high impact strength and excellent environmentalstress cracking resistance.

In another aspect of the present invention, there is provided a processfor producing the ethylene copolymer comprising a copolymer of ethylenewith at least one comonomer selected from the group consisting of acompound represented by the formula H₂C═CHR wherein R is a C₁–C₂₀linear, branched or cyclic alkyl group or a C₆–C₂₀ aryl group, and aC₄–C₂₀ linear, branched or cyclic diene, which process comprisescopolymerizing said ethylene with said comonomer by slurrypolymerization in the presence of a solid catalyst system comprising: asupport, a transition metal compound, and an activator capable ofconverting the transition metal compound into a catalytically activetransition metal complex wherein said solid catalyst system comprises;

1) a supported catalyst component comprising (a) a support material, anorganometal compound wherein the metal is selected form Groups 2–13 ofthe Periodic Table of the Elements, germanium, tin, and lead, and (b) anactivator compound comprising (b-1) a cation which is capable ofreacting with a transition metal compound to form a catalytically activetransition metal complex, and (b-2) a compatible anion having up to 100nonhydrogen atoms and containing at least one substituent comprising anactive hydrogen moiety; and

2) a transition metal compound.

In still another aspect of the present invention, there is provided aprocess for producing the above-defined ethylene copolymer, wherein thetransition metal compound contains at least one cyclic or noncyclicπ-bonded anionic ligand group.

The ethylene copolymer of the present invention is a copolymer ofethylene with at least one comonomer selected from the group consistingof a compound represented by the formula H₂C═CHR wherein R is a C₁–C₂₀linear, branched or cyclic alkyl group or a C₆–C₂₀ aryl group, and aC₄–C₂₀ linear, branched or cyclic diene.

The ethylene copolymer of the present invention has a density d (g/cm³)of from 0.870 to 0.980. Ethylene copolymers having a density d of lowerthan 0.870 g/cm³ cannot be produced very well by slurry polymerization.On the other hand, when an ethylene copolymer has a density d (g/cm³) ofhigher than 0.980, the comonomer content of such a copolymer is too low,so that it is likely that the copolymer has substantially the sameproperties as those of an ethylene homopolymer, but does not havevarious excellent properties characteristic of a copolymer having adensity d (g/cm³) within the above-defined range. In the presentinvention, it is preferred that the ethylene copolymer have a density d(g/cm³) of from 0.87 to 0.980, more preferably from 0.890 to 0.965, andmost preferably from 0.915 to 0.955.

The ethylene copolymer of the present invention has an M_(w)/Mn of from2.5 to 10, wherein Mw and Mn are, respectively, the weight averagemolecular weight and the number average molecular weight, both asmeasured by gel permeation chromatography (GPC). The ratio M_(w)/Mn isused as a criterion for molecular weight distribution. In the presentinvention, when an ethylene copolymer has an M_(w)/Mn of smaller than2.5, the molecular weight distribution of the copolymer is too narrow,so that it becomes difficult for the ethylene copolymer to have thespecific comonomer content distribution characteristic defined in thepresent invention. On the other hand, when an ethylene copolymer has anM_(w)/Mn of larger than 10, it is likely that the impact resistance ofthe copolymer becomes disadvantageously low. Further, in the presentinvention, it is preferred that the ethylene copolymers have an M_(w)/Mnof from 2.8 to 8, more preferably from 3 to 7.

The ethylene copolymer in the present invention has a melt index, (I₂),of from 0.0001 to 10000, preferably from 0.001 to 5000. more preferablyfrom 0.01 to 3000 g/10 min.

The I_(21.6)/I₂ ratio of the ethylene copolymer of the present inventionis from 15 to 65, preferably from 18 to 55, more preferably from 20 to50, or an I₁₀/I₂ ratio of from 5 to 30, preferably from 5 to 28, morepreferably from 5.5 to 25.

With respect to the ethylene copolymer of the present invention, when,in cross fractionation chromatography (CFC) of the ethylene copolymer ofthe present invention, with respect to extraction at an arbitrarytemperature T(° C.) falling within the range of between a firsttemperature at which a maximum amount of extraction is exhibited and asecond temperature which is the lower temperature of either thetemperature of 10° C. higher than said first temperature or 96° C. therelationship between the arbitrary temperature T(° C.) and a point inmolecular weight on a molecular weight distribution profile of acopolymer fraction extracted at the arbitrary temperature T(° C.) atwhich point in molecular weight the molecular weight distributionprofile of the copolymer fraction shows a peak having a maximumintensity is treated by the least squares method to obtain anapproximate straight line within the range of between said firsttemperature and said second temperature; if there is the copolymerfraction the amount of which is less than 1% by weight on the totalamount, excluding purge, of copolymer fraction extracted at temperaturesin the overall range of extraction temperatures in CFC, the copolymerfraction can be excluded from the calculation for the approximatestraight line; the approximate straight line has a gradient within therange defined by the formula (I):−1≦{log Mp(T ¹)−log Mp(T ²)}/(T ¹ −T ²)≦−0.005  (I)wherein:

-   -   T¹ and T² are two different arbitrary extraction temperatures        T(° C.) within the range of between the first temperature and        the second temperature, and    -   Mp(T¹) and Mp(T²) are, respectively, molecular weights        corresponding to T¹ and T² on said approximate straight line.

In the above formula (I), the term {log Mp(T¹)−log Mp(T²)}(T¹−T²)indicates a gradient of the above-mentioned approximate straight line.

In the present invention, the cross fraction chromatography (CFC) isconducted using CFC T-150A (manufactured and sold by Mitsubishi KagakuCorp., Japan). The measurement by CFC is conducted as follows. 20 mg ofa sample is dissolved in 20 ml of dichlorobenzene having a temperatureof 140° C., to thereby obtain a solution of the sample. Then, 5 ml ofthe obtained solution is added to a TREF (temperature rising elutionfractionation) column filled with glass beads, and the solution isallowed to cool to 0° C. at a rate of 1° C./min. Subsequently, thesolution is heated, so as to elevate the temperature of the solution ata rate of 1° C./min, thereby extracting copolymer fractions. Then, theextracted copolymer fractions are subjected to gel permeationchromatography (GPC) using a GPC column Shodex AD806MS (manufactured andsold by Showa Denko K.K., Japan), followed by Fourier transformationinfrared spectroscopy (FT-IR) using Nicolet Manga—IR spectrometer 550(manufactured and sold by Nicolet Co., Ltd., U.S.A.).

With respect to further details of the method for conducting CFC,reference can be made to the catalogue attached to the above-mentionedCFC T-150A.

With respect to conventional ethylene copolymers produced using aconventional Ziegler catalyst, the gradient {log Mp(T¹)−logMp(T²)}/(T¹−T²) is generally almost 0 or of a positive value. Withrespect to conventional ethylene 5 copolymers produced usingconventional metallocene catalysts which have recently been being putinto practical use, the gradient {log Mp(T¹)−log Mp(T²)}/(T¹−T²) isalmost 0.

As already mentioned above, in the present invention, when, in crossfractionation chromatography (CFC) of the ethylene copolymer of thepresent invention, with respect to extraction at an arbitrarytemperature T(° C.) falling within the range of between a firsttemperature at which a maximum amount of extraction is exhibited and asecond temperature which is the lower temperature of either thetemperature of 10° C. higher than said first temperature or 96° C., therelationship between the arbitrary temperature T(° C.) and a point inmolecular weight on a molecular weight distribution profile of acopolymer fraction extracted at the arbitrary temperature T(° C.) atwhich point in molecular weight the molecular weight distributionprofile of the copolymer fraction shows a peak having a maximumintensity is treated by the least squares method to obtain anapproximate straight line, the approximate straight line has a gradient[that is, {log Mp(T¹)−log Mp(T²)}/(T¹−T²)] which has negative value.This that the copolymer fraction extracted at a low temperature, that isa low density copolymer fraction having a high comonomer content, has ahigher molecular weight than that of the copolymer fraction extracted ata high temperature, that is , a high density copolymer fraction having alow comonomer content.

The ethylene copolymer of the present invention has a gradient [{logMp(T¹)−log Mp(T²)}/(T¹−T²)] which is considerably large in negativevalue (within the range of from −0.005 to −1). This clearly indicatesthat, in the ethylene copolymer of the present invention, a copolymerfraction having a high comonomer content has a high molecular weight,contrary to the conventional ethylene copolymers, in which a copolymerfraction having a high comonomer content typically has a low molecularweight.

Further, the ethylene copolymer of the present invention has a gradient[{log Mp(T¹)−log Mp(T²)}/(T¹−T²)] in negative value within a range offrom −0.005 to −1. This indicates that the copolymers having copolymerfractions of widely varied comonomer contents and widely variedmolecular weights can be obtained within the above-mentioned range ofthe gradient, which copolymer fractions widely vary from a low molecularweight copolymer fraction having a low comonomer content, that is, ahigh density copolymer fraction having a low molecular weight, to a highmolecular weight copolymer fraction having a high comonomer content,that is, a low density copolymer fraction having a high molecularweight. The copolymers of the present invention, which have differentcomonomer contents, exhibit excellent miscibility to each other or oneanother. Therefore, in the present invention, the copolymers havingdifferent comonomer contents can be blended, so as to obtain a copolymerhaving desired properties, without occurrence of gel formation.

However, when the gradient [{log Mp(T¹)−log Mp(T²)}/(T¹−T²)] becomes toosmall it becomes difficult to obtain a designed copolymer having adesired structure and properties. Therefore, in the present invention,the gradient must be −1 or more. Further, in the present invention, thegradient be preferably within the range defined by the formula:−0.5≦{log Mp(T ¹)−log Mp(T ²)}/(T ¹ −T ²)≦−0.007;preferably,−0.1≦{log Mp(T ¹)−log Mp(T ²)}/(T ¹ −T ²)≦−0.01;more preferably,−0.08≦{log Mp(T ¹)−log Mp(T ²)}/(T ¹ −T ²)≦−0.02;wherein T¹, T², Mp(T¹) and Mp(T²) are as defined for the formula (I).

When the ethylene copolymer of the present invention is measured by CFC,the ethylene copolymer shows characteristics such that the sum ofrespective amounts of copolymer fractions extracted at temperatureswhich are at least 10° C. lower than the first temperature as definedabove is 8% by weight or less, based on the total amount, excludingpurge, of copolymer fractions extracted at temperatures in the overallrange of extraction temperature in CFC. In the present invention theabove-mentioned sum of respective amounts of copolymer fractions can beobtained from an integral curve showing the amounts of extractedcopolymer fraction, relative to extraction temperatures.

On the other hand, when conventional ethylene copolymers, produced usinga Ziegler-Natta catalyst, are measured by CFC, the ethylene copolymersshow characteristics such that a relatively large amount of copolymerfractions are extracted at temperatures which are at least 10° C. lowerthan the first temperature as defined above, as shown by ComparativeExamples 4 through 6. This indicates that such ethylene copolymers havea broad distribution of composition and contains low molecular weightwaxy components or extremely low density copolymer fractions.

Conventionally, it has been considered that the ethylene copolymersproduced using metallocene catalysts, which have recently been being putinto practical use, have a narrow distribution in comonomer content.However, when some of such-ethylene copolymers are subjected to CFCmeasurement, a considerably large amount of copolymer fractions areextracted within a wide range of temperatures which are at least 10° C.lower than the first temperature as defined above.

In the case of the ethylene copolymer of the present invention, theamount of such copolymer fractions extracted at temperatures which areat least 10° C. lower than the first temperature as defined above areextremely small. Specifically, when the ethylene copolymer of thepresent invention is measured by CFC, the ethylene copolymer showscharacteristics such that the sum of respective amounts of copolymerfractions extracted at temperatures which are at least 10° C. lower thanthe first temperature as defined above is 8% by weight or less,preferably 5% by weight or less, more preferably 3.5% by weight or less,based on the total amount of copolymer fractions extracted attemperatures in the overall range of extraction temperatures in CFC, butexcluding the purge.

Due to such an extremely small content of the copolymer fractionsextracted at temperatures which are at least 10° C. lower than the firsttemperature as defined above, the ethylene copolymer of the presentinvention has excellent properties, for example, a freedom of adverseeffects caused by the presence of waxy components and low densitycopolymer fractions. Further in the present invention, it is possible toproduce copolymers having a very low density and a very low molecularweight. Such copolymers can be advantageously mixed for providing a widevariety of mixtures, each comprising two or more different copolymercomponents having different comonomer contents. Therefore, it becomespossible to design various mixtures having desired properties by the useof the above-mentioned copolymers having a very low density and a verylow molecular weight. This is very advantageous from the commercialpoint of view.

In the present invention, within a range in molecular weight of theethylene copolymer which is defined by the formula (II):log(Mt)−log(Mc)≦0.5  (II)wherein:

-   -   Mt is a point in molecular weight on a molecular weight        distribution profile at which the profile shows a peak having a        maximum intensity, and    -   Mc is an arbitrary point in molecular weight on the molecular        weight distribution profile,    -   the molecular weight distribution profile being obtained        together with a comonomer content distribution profile by        subjecting the ethylene copolymer to gel permeation        chromatography/Fourier transformation infrared spectroscopy        (GPC/FT-IR),        an approximate straight line obtained from the comonomer content        distribution profile by the least squares method has a gradient        within the range defined by the formula (III):        0.0005≦{C(Mc ¹)−C(Mc ²)}/(log Mc ₁−log Mc ²)≦0.05  (III)        wherein:    -   Mc¹ and Mc² are two different arbitrary points (Mc) in molecular        weight which satisfy the formula (II), and    -   C(Mc¹) and C(Mc²) are, respectively, comonomer contents        corresponding to Mc¹ and Mc² on the approximate straight line.

As mentioned above, the molecular weight distribution profile and thecomonomer content distribution profile can be obtained by subjecting theethylene copolymer to gel permeation chromatography/Fouriertransformation infrared spectroscopy (GPC/FT-IR). In the presentinvention, the measurement by GPC is conducted using 150C ALC/GPC(manufactured and sold by Waters Assoc. Co. U.S.A.), in which threecolumns [one Shodex AT-807S (manufactured and sold by Showa Denko K.K.,Japan) and two TSK-gel GMH-H6 (manufactured and sold by Tosoh Corp.,Japan)], which are connected in series, are used, and the measurement byFT-IR is conducted by dissolving 20 to 30 mg of a sample in 15 ml oftrichlorobenzene having a temperature of 140° C., and applying 500 to1.000 μl of the resultant solution to a FT-IR apparatus (PERKIN-ELMER1760X. manufactured and sold by Perkin Elmer Cetus, Co., Ltd., U.S.A.).

In the present invention, the comonomer content is defined as a valueobtained by dividing the number of comonomer units relative to 1,000methylene units contained in the copolymer, by 1,000. For example, when5 comonomer units are contained relative to 1,000 methylene units, thecomonomer content is 0.005. The value of the comonomer content can beobtained from the ratio of the intensity of an absorbance attributed tothe comonomer units to the intensity of an absorbance attributed to themethylene units, which ratio can be obtained by FT-IR. For example, whena linear α-olefin is used as a comonomer, the ratio of the intensity ofabsorbance at 2,960 cm⁻¹, which is attributed to the methyl groups, tothe intensity of absorbance at 2,925 cm⁻¹, which is attributed to themethylene groups, is obtained by FT-IR. From the obtained ratio, thecomonomer content can be obtained.

Generally, the above-mentioned comonomer content distribution profile isshown as a line containing points indicating comonomer contents. Forimproving the accuracy of the profile, it is desirable to obtain a largenumber of points indicating the comonomer contents by repeatedlyconducting the comonomer content measurement using the same sample underthe same conditions. In the present invention, within the above-definedrange in molecular weight of the ethylene copolymer, an approximatestraight line is obtained from the obtained points of comonomer contentdistribution profile by the least squares method.

In the present invention, the gradient of the approximate straight lineobtained from the comonomer content distribution profile is defined bythe following formula:{C(Mc ¹)−C(Mc ²)}/(log Mc ¹−log Mc ²)wherein:

-   -   Mc¹ and Mc² are two different arbitrary points (Mc) in molecular        weight which satisfy the formula (II), and    -   C(Mc¹) and C(Mc²) are, respectively, comonomer contents        corresponding to Mc¹ and Mc² on the approximate straight line.

The comonomer content distribution profile indicates the comonomercontents of copolymer fractions of various molecular weights, and thegradient of the approximate straight line obtained from the profile bythe least squares rnethodindicates the change in comonomer content,relative to the change in molecular weight of the copolymer fraction.

With respect to the ethylene copolymers produced using a conventionalZiegler catalyst, the above-mentioned gradient of the approximatestraight line has a negative value. This indicates that suchconventional ethylene copolymers have a comonomer content distributionsuch that the higher the molecular weight of a copolymer fraction, thelower the comonomer content of the copolymer fraction.

Even in the case of ethylene copolymers produced using conventionalmetallocene catalysts which have recently been being put into practicaluse, the above-mentioned gradient of approximate straight line obtainedfrom the comonomer content distribution profile by the least squaresmethod is almost 0. Even if the errors in measurement are considered,the gradient is smaller than 0.0001.

On the other hand, the ethylene copolymer of the present invention hasthe above-mentioned gradient [{C(Mc¹)−C(Mc²)}/(log Mc¹−log Mc²)] of0.0005 or more, within the above-defined range in molecular weight ofthe ethylene copolymer.

This clearly indicates that the ethylene copolymer of the presentinvention has a specific comonomer content distribution such that, inone aspect, the lower the molecular weight of a copolymer fraction, thelower the comonomer content of the copolymer fraction; and, in the otheraspect, the higher the molecular weight of a copolymer fraction, thehigher the comonomer content of the copolymer fraction. Due to such aspecific comonomer content distribution, the ethylene copolymer of thepresent invention exhibits various excellent properties, such as highimpact strength and excellent ESCR properties, as compared to theconventional ethylene copolymers.

In the present invention, it is preferred that, within the above-definedrange in molecular weight of the ethylene copolymer, the above-mentionedgradient be within the range defined by the formula (IV):0.001≦{C(Mc ¹)−C(Mc ²)}/(log Mc ¹−log Mc ²)≦0.02  (IV)wherein Mc¹, Mc², C(Mc¹) and C(Mc²) are as defined for the formula(III).

In the present invention, there is provided a process for obtaining anovel ethylene copolymer.

Specifically, the process comprises copolymerizing ethylene with atleast one comonomer selected from the group consisting of a compoundrepresented by the formula H₂C═CHR wherein R is a C₁–C₂₀ linear,branched or cyclic alkyl group or a C₆–C₂₀ aryl group, and a C₄–C₂₀linear, branched or cyclic diene by slurry polymerization in thepresence of a solid catalyst system comprising:

a support, a transition metal compound, and an activator capable ofconverting the transition metal compound into a catalytically activetransition metal complex.

The reasons for obtaining the unexpected and surprising copolymerproperties with the process of the present invention are believed to beas follows.

As already mentioned above, the ethylene copolymer of the presentinvention has a specific comonomer content distribution such that, inone aspect, the lower the molecular weight of a copolymer fraction, thelower the comonomer content of the copolymer fraction; and, in the otheraspect, the higher the molecular weight of a copolymer fraction, thehigher the comonomer content of the copolymer fraction.

In addition, for producing the ethylene copolymer of the presentinvention, the following requirements have to be satisfied:

-   (i) the produced polymer must not be melted in the reaction mixture    but maintains the solid state;-   (ii) the polymerization rate at the active species of the catalyst    is satisfactorily high; and-   (iii) the active species of the catalyst is strongly associated with    a carrier, so that the active species of the catalyst is not    liberated from the carrier and does not escape from the polymer    being produced.

Further, the larger the particle size of a polymer being produced, theeasier it becomes to achieve a comonomer content distributioncharacteristic of the ethylene copolymer of the present invention,namely, a specific comonomer content distribution such that, in oneaspect, the lower the molecular weight of a copolymer fraction, thelower the comonomer content of the copolymer fraction; and, in the otheraspect, the higher the molecular weight of a copolymer fraction, thehigher the comonomer content of the copolymer fraction.

In the method of the present invention for producing an ethylenecopolymer, the above-mentioned requirements are satisfied, so that thepolymerization reaction can proceed as is explained below.

First, in the method of the present invention, the polymerizationreaction is conducted by slurry polymerization, so that the producedpolymer is not melted, but maintains the solid state, during thereaction. Therefore, requirement (i) is satisfied.

Second, the preferred catalyst systems to be used in the presentinvention contain a transition metal compound, that is, a compound of atransition metal of a Group selected from Groups 3 to 5 of the PeriodicTable, wherein the compound contains at least one, preferably only onecyclic π-bonded anionic ligand. Such preferred transition metalcompounds, having only one cyclic π-bonded anionic ligand, have a largespace around the transition metal, as compared to the space around thetransition metal of a metallocene catalyst which contains two or morecyclic or non-cyclic π-bonded anionic ligands. Therefore, with respectto a transition metal compound having only one cyclic or non-cyclicπ-bonded anionic ligand, the access of a bulky comonomer to thetransition metal is not inhibited, thus enabling the reaction to proceedsmoothly. In addition, the preferred catalyst system to be used in themethod of the present invention contains a solid component which servesto achieve a high polymerization rate. Therefore, with the catalystsystem to be used in the present invention, the rate of polymerizationat the active species of the catalyst is satisfactorily high. Hence, themethod of the present invention satisfies requirement (ii) above.

Third, in the preferred catalyst systems to be used in the presentinvention, the active species of the catalyst is strongly associatedwith a carrier, so that the active species of the catalyst is notliberated from the carrier and does not escape from the polymer beingproduced.

Specifically stated, in one preferred supported catalyst component to beused in the process of the present invention, the active hydrogen moietyof the activator compound may be bonded to the hydroxyl groups of thesupport material through an organometal compound. That is, the activatorcompound is strongly bonded to and carried on the support material. In afurther preferred supported catalyst component to be used in the presentinvention, alumoxane is fixed to the support material by a heatingand/or washing treatment, such that the alumoxane is substantially notextractable under severe conditions (toluene at 90° C.). Therefore,requirement (iii) above is met.

The ethylene copolymer of the present invention can be advantageouslyproduced by the method of the present invention using the catalystsystem described above, and the catalytic system is especially effectivewhen a catalyst has a relatively large particle size and when the bulkof the comonomer is relatively large.

As described above, the production of the ethylene copolymer of thepresent invention is enabled only when all of the above-mentionedrequirements are simultaneously satisfied. The present inventors havefor the first time unexpectedly found the above-mentioned requirementsfor the production of the excellent ethylene copolymer of the presentinvention.

Hereinbelow, the method for producing the ethylene copolymer of thepresent invention will be explained in more detail.

The ethylene copolymer of the present invention is advantageouslyproduced by copolymerizing ethylene with a comonomer using a specificsolid catalyst.

Suitable support materials for use in the present invention includeporous resinous materials, for example, polyolefins such aspolyethylenes and polypropylenes or copolymers ofstyrene-divinylbenzene, and solid inorganic oxides including oxides ofGroup 2, 3, 4, 13, or 14 metals, such as silica, alumina, magnesiumoxide, titanium oxide, thorium oxide, as well as mixed oxides of silica.Suitable mixed oxides of silica include those of silica and one or moreGroup 2 or 13 metal oxides, such as silica-magnesia or silica-aluminamixed oxides. Silica, alumina, and mixed oxides of silica and one ormore Group 2 or 13 metal oxides are preferred support materials.Preferred examples of such mixed oxides are the silica-aluminas. Themost preferred support material is silica. The shape of the silicaparticles is not critical and the silica may be in granular, spherical,agglomerated, fumed or other form. Suitable silicas include those thatare available from Grace Davison (division of W.R. Grace & Co.) underthe designations SD 3216.30, SP-9-10046, Davison Syloid™ 245, Davison948 and Davison 952, from Degussa AG under the designation Aerosil™ 812,and from Crossfield under the designation ES 70X.

Support materials suitable for the present invention preferably have asurface area as determined by nitrogen porosimetry using the B.E.T.method from 10 to 1000 m²/g, and preferably from 100 to 600 m²/g. Thepore volume of the support, as determined by nitrogen adsorption, istypically up to 5 cm³/g, advantageously between 0.1 and 3 cm³/g,preferably from 0.2 to 2 cm³/g. The average particle size is notcritical but typically is from 0.5 to 500 μm, preferably from 1 to 200μm, more preferably to 100 μm.

The support material may be subjected to a heat treatment and/orchemical treatment to reduce the water content or the hydroxyl contentof the support material. Both dehydrated support materials and supportmaterials containing small amounts of water can be used. Typical thermalpretreatments are carried out at a temperature from 30° C. to 1000° C.for a duration of 10 minutes to 50 hours in an inert atmosphere or underreduced pressure. Typical support materials have a surface hydroxylcontent of from 0.1 micromol, preferably from 5 micromol, morepreferably from 0.05 mmol to not more than 10 mmol and preferably notmore than 5 mmol hydroxyl groups per g of solid support, more preferablyfrom 0.5 to 2 mmol per gram. The hydroxyl content can be determined byknown techniques, such as infrared spectroscopy and titration techniquesusing a metal alkyl or metal hydroxide, for example, adding an excess ofdialkyl magnesium to a slurry of the solid support and determining theamount of dialkyl magnesium remaining in solution via known techniques.This latter method is based on the reaction ofS—OH+MgR₂→S—OMgR+RH,wherein S is the solid support.

As an alternative technique for measuring the amount of hydroxyl groupson the surface of the inorganic solid, a method comprising the followingprocedures can be utilized. Illustratively stated, the inorganic solidis dried in a nitrogen gas flow at 250° C. for 10 hours and then, theweight of the dried inorganic solid is measured and taken as an initialweight represented by “W1” (unit: g). After this, the dried inorganicsolid is heated to 1,000° C. and then, allowed to cool to the roomtemperature. The weight of the cooled inorganic solid is measured, andthe difference between the initial weight (W1) and the weight of thecooled inorganic solid is determined and taken as a weight lossrepresented by “ΔW” (unit: g). The amount of the hydroxyl groups wascalculated by the following formula:Amount of the hydroxyl groups=(1,000×ΔW/18.02)/W1 mmol/g  (V)

It is preferred that the inorganic solid having hydroxyl groups on thesurface thereof to be used in the method of the present invention doesnot contain water such as crystal water or adsorbed water.

Any water contained in the inorganic solid can be removed therefrom byheating in a nitrogen atmosphere or under reduced pressure at 250° C. ormore for 1 hour or more.

Suitable transition metal compounds for use in the present invention arethose that can be converted by an activator compound (b) to thereby forma catalytically active transition metal complex. The transition metalcompounds may be derivatives of any transition metal includingLanthanides, preferably from Groups 3, 4, 5, and 6, more preferably theGroup 3 or 4 transition metals or the Lanthanides, which transitionmetals are in the +2, +3, or +4 formal oxidation state. The transitionmetals preferably contain at least one π-bonded anionic ligand groupwhich can be a cyclic or noncyclic delocalized π-bonded anioligandgroup. Exemplary of such π-bonded anionic ligand groups are conjugatedor non-conjugated, cyclic or non-cyclic dienyl groups, allyl groups,aryl groups, as well as substituted derivatives of such groups.

The term “derivative” when used to describe the above-substituted,delocalized π-bonded groups means that each atom in the delocalizedπ-bonded group may independently be substituted with a radical selectedfrom the group consisting of halogen, hydrocarbyl, halohydrocarbyl, andhydrocarbyl-substituted metalloid radicals wherein the metalloid isselected from Group 14 of the Periodic Table of the Elements. Includedwithin the term “hvdrocarbyl” are C₁₋₂₀ straight, branched and cyclicalkyl radicals, C₆₋₂₀ aromatic radicals, C₇₋₂₀ alkyl-substitutedaromatic radicals, and C₇₋₂₀ aryl-substituted alkyl radicals. Inaddition two or more such radicals may together form a fused ring systemor a hydrogenated fused ring system. Suitable hydrocarbyl-substitutedorgano-metalloid radicals include mono-, di- and tri-substitutedorgano-metalloid radicals of Group 14 elements wherein each of ihehydrocarbyl groups contains from 1 to 20 carbon atoms. Moreparticularly, suitable hydrocarbyl-substituted organo-metalloid radicalsinclude trimethylsilyl, triethylsilyl, ethyldimethylsilyl,methyldiethylsilyl, triphenylgermyl. trimethylgermyl.

Preferred anionic, delocalized π-bonded groups include cyclopentadienyland substituted cyclopentadienyl groups. Especially preferred arecyclopentadienyl, indenyl, fluorenyl, tetrahydroindenyl,tetrahydrofluorenyl, and octahydrofluorenyl. Other examples of preferredanionic ligand groups are pentadienyl, cyclohexa dienyl,dihydroanthracenyl, hexahydroanthracenyl, and decahydroanthracenylgroups, and methyl-substituted derivatives thereof.

Suitable transition metal compounds (c) may be a cyclopentadienyl orsubstituted cyclopentadienyl derivative of any transition metalincluding Lanthanides, but preferably of the Group 3, 4, or Lanthanidetransition metals. Suitable transition metal compounds for use in thepresent invention are the bridged or unbridged mono-, bis-, andtri-cyclopentadienyl or substituted cyclopentadienyl transition metalcompounds.

Suitable unbridged monocyclopentadienyl or mono(substitutedcyclopentadienyl) transition metal derivatives are represented by thefollowing formula (VI):CPMX_(n)  (VI)wherein Cp is cyclopentadienyl or a derivative thereof, M is a Group 3,4, or 5 transition metal having a formal oxidation state of +2, +3 or+4, X independently in each occurrence represents an anionic ligandgroup (other than a cyclic, aromatic π-bonded anionic ligand group)selected from the group of hydrocarbyl, hydrocarbvlene (includinghydrocarbadienyl), hydrocarbyloxy, hydride, halo, silyl, germyl, amide,and siloxy radicals having up to 50 nonhydrogen atoms, and n, a numberequal to one less than the formal oxidation state of M, is 1, 2 or 3,preferably 3. Preferably, at least one of X is a hydrocarbyl radicalhaving from 1 to 20 carbon atoms, a substituted-hydrocarbyl radicalhaving from 1 to 20 carbon atoms wherein one or more of the hydrogenatoms are replaced with a halogen atom, or an organo-metalloid radicalcomprising a Group 14 element wherein each of the hydrocarbylsubstituents contained in the organo portion of said organo-metalloid,independently, contain from 1 to 20 carbon atoms.

Suitable bridged monocyclopentadienyl or mono(substitutedcyclopentadienyl) transition metal compounds include the so-calledconstrained geometry complexes. Examples of such complexes and methodsfor their preparation are disclosed in U.S. application Ser. No.545,403, filed Jul. 3, 1990 (corresponding to EP-A-416,815), U.S.application Ser. No. 241,523, filed May 12, 1994, now U.S. Pat. No.5,470,993 (corresponding to WO-95/00526), as well as U.S. Pat. Nos.5,055,438; 5,057,475; 5,096,867; 5,064,802; 5,132,380 and 5,374,696; allof which are incorporated herein by reference.

More particularly, preferred bridged monocyclopentadienyl ormono(substituted cyclopentadienyl) transition metal compounds correspondto the following formula (VII):

wherein:

-   -   M is a metal of Group 3–5, especially a Group 4 metal,        particularly titanium:    -   Cp* is a substituted cyclopentadienyl group bound to Z′ and, in        an η⁵ bonding mode, to M or such a group is further substituted        with from one to four substituents selected from the group        consisting of hydrocarbyl, silyl, germyl, halo, hydrocarbyloxy,        amine, and mixtures thereof, said substituent having up to 20        nonhydrogen atoms, or optionally, two such further substituents        together cause Cp* to have a fused ring structure;    -   Z′ is a divalent moiety other than a cyclic or noncyclic        π-bonded anionic ligand, said Z′ comprising boron, or a member        of Group 14 of the Periodic Table of the Elements, and        optionally nitrogen, phosphorus, sulfur or oxygen, said moiety        having up to 20 non-hydrogen atoms, and optionally Cp* and Z′        together form a fused ring system;    -   X independently each occurrence represents an anionic ligand        group (other than a cyclic, aromatic π-bonded anionic ligand        group) selected from the group of hydrocarbyl, hydrocarbylene        (including hydrocarbadienyl), hydrocarbyloxy, hydride, halo,        silyl, germyl, amide, and siloxy radicals having up to 50        nonhydrogen atoms, preferably X is selected from the group of a        hydride radical, hydrocarbyl radical, substituted-hydrocarby i        radical, or organo-metalloid radical; and    -   n is 1 or 2 depending on the valence of M.

In consonance with the previous explanation, M is preferably a Group 4metal, especially titanium; n is 1 or 2; and X is monovalent ligandgroup of up to 30 nonhydrogen atoms, more preferably, C₁₋₂₀ hydrocarbyl.

When n is 1 and the Group 3–5 metal (preferably the Group 4 metal) is inthe +3 formal oxidation state, X is preferably a stabilizing ligand.

By the term “stabilizing ligand” is meant that the ligand groupstabilizes the metal complex through either:

-   -   1) a nitrogen, phosphorus, oxygen or sulfur chelating bond, or    -   2) an η³ bond with a resonant, delocalized π-electronic        structure.

Examples of stabilizing ligands of group 1) include silyl, hydrocarbyl,amido or phosphido ligands substituted with one or more aliphatic oraromatic ether, thioether, amine or phosphine functional groups,especially such amine or phosphine groups that are tertiary-substituted,said stabilizing ligand having from 3 to 30 nonhydrogen atoms. Mostpreferred group 1) stabilizing ligands are 2-dialkylaminobenzyl or2-(dialkylaminomethyl)-phenyl groups containing from 1 to 4 carbons inthe alkyl groups.

Examples of stabilizing ligands of group 2) include C₃₋₁₀ hydrocarbylgroups containing ethylenic unsaturation, such as allyl, 1-methylallyl,2-methylallyl, 1,1-dimethylallyl, or 1,2,3-trimethylallyl groups.

More preferably still, such metal coordination complexes correspond tothe following formula (VIII):

-   -   wherein R′ in each occurrence is independently selected from the        group consisting of hydrogen, hydrocarbyl, silyl, germyl, cyano,        halo and combinations thereof having up to 20 nonhydrogen atoms,        or two R′ groups together form a divalent derivative thereof;    -   X has the same meaning as defined for formula (VI);    -   Y is a divalent anionic ligand group comprising nitrogen,        phosphorus, oxygen or sulfur and having up to 20 non-hydrogen        atoms, said Y being bonded to Z and M through said nitrogen,        phosphorus, oxygen or sulfur, and optionally Y and Z together        form a fused ring system;    -   M is a Group 4 metal, especially titanium; Z is SiR*₂, CR*₂,        SiR*₂SiR*₂, CR*₂CR*₂, CR*═CR*, CR*₂SiR*₂, GeR*₂, BR*, or BR*₂;        wherein:    -   R* in each occurrence is independently selected from the group        consisting of hydrogen, hydrocarbyl, silyl, halogenated alkyl,        halogenated aryl groups having up to 20 non-hydrogen atoms, and        mixtures thereof, or two or more R* groups from Z, or an R*        group from Z together with Y form a fused ring system; and    -   n is 1 or 2.

Further more preferably, Y is —O—, —S—, —NR*—, —PR*—. Highly preferablyY is a nitrogen or phosphorus containing group corresponding to theformula —N(R′)— or —P(R′)—, wherein R′ is as previously described, thatis , an amido or phosphido group.

Most highly preferred metal coordination complexes correspond to thefollowing formula (IX):

wherein:

-   -   M is titanium;    -   R′ each occurrence is independently selected from the group        consisting of hydrogen, silyl, hydrocarbyl and combinations        thereof having up to 10 carbon or silicon atoms, or two R′        groups of the substituted cyclopentadienyl moiety are joined        together;    -   E is silicon or carbon;    -   X independently each occurrence is hydride, alkyl, aryl, of up        to 10 carbons;    -   m is 1 or 2; and    -   n is 1 or 2.

Examples of the above most highly preferred metal coordination compoundsinclude compounds wherein the R′ on the amido group is methyl, ethyl,propyl, butyl, pentyl, hexyl, (including isomers), norbornyl, benzyl,phenyl, and cyclododecyl; (ER′₂)_(m) is dimethyl silane or 1,2-ethylene;R′ on the cyclic π-bonded group independently each occurrence ishydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, norbornyl,benzyl, and phenyl, or two R′ groups are joined forming an indenyl,tetrahydroindenyl, fluorenyl or octahydrofluorenyl moiety; and X ismethyl, ethyl, propyl, butyl, pentyl, hexyl, norbornyl, benzyl, andphenyl.

Transition metal compounds wherein the transition metal is in the +2formal oxidation state include those complexes containing one and onlyone cyclic, delocalized, anionic, π-bonded group, said complexescorresponding to the following formula (X):

wherein:

-   -   M is titanium or zirconium in the +2 formal oxidation state;    -   L is a group containing a cyclic, delocalized, anionic, π-system        through which the group is bonded to M. and which group is also        bonded to Z;    -   Z is a moiety bonded to M via a σ-bond, comprising boron, or a        member of Group 14 of the Periodic Table of the Elements, and        also comprising nitrogen, phosphorus, sulfur or oxygen, said        moiety having up to 60 non-hydrogen atoms; and    -   X* is a neutral, conjugated or nonconjugated diene, optionally        substituted with one or more hydrocarbyl groups, said X having        up to 40 carbon atoms and forming a π-complex with M.

Preferred transition metal compounds of formula (X) include thosewherein Z, M and X* are as previously defined; and L is a C₅H₄ groupbonded to Z and bound in an η⁵ bonding mode to M or is such an η⁵ boundgroup substituted with from one to four substituents independentlyselected from hydrocarbyl, silyl, germyl, halo, cyano, and combinationsthereof, said substituent having up to 20 nonhydrogen atoms, andoptionally, two such substituents (except cyano or halo) together causea fused ring structure.

More preferred transition metal +2 compounds according to the presentinvention correspond to the following formula (XI)):

-   -   wherein:    -   R′ in each occurrence is independently selected from hydrogen,        hydrocarbyl, silyl, germyl, halo, cyano, and combinations        thereof, said R′ having up to 20 nonhydrogen atoms, and        optionally, two R′ groups (where R′ is not hydrogen, halo or        cyano) together form a divalent derivative thereof connected to        adjacent positions of the cyclopentadienyl ring to form a fused        ring structure;    -   X* is a neutral η⁴-bonded diene group having up to 30        nonhydrogen atoms, which forms a π-complex with M;    -   Y is —O—, —S—, —NR*—, —PR*—;    -   M is titanium or zirconium in the +2 formal oxidation state;    -   Z* is SiR*₂, CR*₂, SiR*₂SiR*₂, CR*₂CR*₂, CR*═CR*, CR*₂SiR*₂, or        GeR*₂; wherein:    -   R* each occurrence is independently hydrogen, or a member        selected from hydrocarbyl, silyl, halogenated alkyl, halogenated        aryl, and combinations thereof, said R* having up to 10        nonhydrogen atoms, and optionally, two R* groups from Z* (when        R* is not hydrogen), or an R* group from Z* and an R* group from        Y form a ring system.

Preferably, R′ independently each occurrence is hydrogen, hydrocarbyl,silyl, halo and combinations thereof said R′ having up to 10 nonhydrogenatoms, or two R′ groups (when R′ is not hydrogen or halo) together forma divalent derivative thereof: most preferably, R′ is hydrogen, methyl.ethyl, propyl, butyl, pentyl, hexyl, (including where appropriate allisomers), cyclopentyl, cyclohexyl, norbornyl, benzyl, or phenyl or twoR′ groups (except hydrogen) are linked together, the entire C₅R′₄ groupthereby being, for example, an indenyl, tetrahydroindenyl, fluorenyl,tetrahydrofluorenyl, or octahydrofluorenyl group.

Further preferably, at least one of R′ or R* is an electron donatingmoiety. By the term “electron donating” is meant that the moiety is moreelectron donating than hydrogen. Thus, highly preferably Y is a nitrogenor phosphorus containing group corresponding to the formula —N(R″)— or—P(R″)—, wherein R″ is C₁₋₁₀ hydrocarbyl.

Examples of suitable X* groups include:s-trans-η⁴-1,4-diphenyl-1,3-butadiene;s-trans-η⁴-3-methyl-1,3-pentadiene;s-trans-η⁴-1,4-dibenzyl-1,3-butadiene; s-trans-η⁴-2,4-hexadiene;s-trans-η⁴-1,3-pentadiene: s-trans-η⁴-1,4-ditolyl-1,3-butadiene;s-trans-η⁴-1,4-bis(trimethylsilyl)-1,3-butadiene;s-cis-η⁴-1,4-diphenyl-1,3-butadiene; s-cis-η⁴-3-methyl-1,3-pentadiene:s-cis-η⁴-1,4-dibenzyl-1,3-butadiene; s-cis-η⁴-2,4-hexadiene;s-cis-η⁴-1,3-pentadiene; s-cis-η⁴-1,4-ditolyl-1,3-butadiene; ands-cis-η⁴-1,4-bis(trimethylsilyl)-1,3-butadiene, said s-cis diene groupforming a π-complex as defined herein with the metal.

Most highly preferred transition metal +2 compounds are amidosilane- oramidoalkanediyl-compounds of formula (XI) wherein:

-   -   —Z*—Y— is —(E′″²)_(m)—N(R″)—, and R′ each occurrence is        independently selected from hydrogen, silyl, hydrocarbyl and        combinations thereof, said R′ having up to 10 carbon or silicon        atoms, or two such R′ groups on the substituted cyclopentadienyl        group (when R′ is not hydrogen) together form a divalent        derivative thereof connected to adjacent positions of the        cyclopentadienyl ring;

-   R″ is C₁₋₁₀ hydrocarbyl;

-   R′″ is independently each occurrence hydrogen or C₁₋₁₀ hydrocarbyl;

-   E is independently each occurrence silicon or carbon; and

-   m is 1 or 2.

Examples of the metal complexes according to the present inventioninclude compounds wherein R″ is methyl, ethyl, propyl, butyl, pentyl,hexyl, (including all isomers of the foregoing where applicable),cyclododecyl, norbornyl, benzyl, or phenyl; (ER′″₂)_(m) isdimethylsilane, or ethanediyl; and the cyclic delocalized π-bonded groupis cyclopentadienyl, tetramethylcyclo-pentadienyl, indenyl,tetrahydroindenyl, fluorenyl, tetrahydrofluorenyl or octahydrofluorenyl.

Suitable bis(cyclopentadienyl) derivatives of transition metals includethose of titanium, zirconium and hafnium compounds and may berepresented by the following general formulae (XII) to (XV):

(A-Cp) MX₁X₂ (XII) (A-CP) MX′₁X′₂ (XIII) (A-Cp) ML (XIV) (Cp*) (CpR) MX₁(XV)wherein: M is a Group 4 metal namely titanium (Ti), zirconium (Zr) andhafnium (Hf); (A-Cp) is either (Cp)(Cp*) or Cp-A′-Cp* and Cp and Cp* arethe same or different cyclopentadienyl radicals, as well as substitutedderivatives of cyclopentadienyl radicals, and A′ is a covalent bridginggroup containing a Group 14 element; L is an olefin, diolefin or aryneligand: at least one of X₁ and X₂ is a hydride radical, hydrocarbylradical, substituted-hydrocarbyl radical, or organo-metalloid radical,the other of X₁ and X₂ being a hydride radical, hydrocarbyl radical,substituted-hydrocarbyl radical, organo-metalloid radical, or ahydrocarbyloxy radical; preferably one or both of X₁ and X₂ is ahydrocarbyl radical having from 1 to 20 carbon atoms,substituted-hydrocarbyl radical having from 1 to 20 carbon atoms whereinone or more of the hydrogen atoms are replaced with a halogen atom,organo-metalloid radical comprising a Group 14 element wherein each ofthe hydrocarbyl substituents contained in the organo portion of saidorgano-metalloid, independently, contain from 1 to 20 carbon atoms; X′₁and X′₂ are joined and bound to the metal atom to form a metallacycle,in which the metal, X′₁ and X′₂ form a hydrocarbocyclic ring containingfrom 3 to 20 carbon atoms; and R is a substituent, preferably ahydrocarbyl substituent, having from 1 to 20 carbon atoms on one of thecyclopentadienyl radicals, which is also bound to the metal atom.

When not both X₁ and X₂ are a hydride radical, hydrocarbyl radical,substituted-hydrocarbyl radical, or organo-metalloid radical one ofthese can be a hydrocarbyloxy radical having from 1 to 20 carbon atoms.Suitable examples of hydrocarbyloxy radicals include alkyloxy, aryloxy,aralkyloxy, and alkaryloxy radicals having from 1 to 20 carbon atoms,more preferably alkyl radicals having from 1 to 6 carbon atoms, andaryl, aralkyl and alkaryl radicals having from 6 to 10 carbon atoms,even more preferably isopropyloxy, n-butyloxy, or t-butyloxy.

Examples of such bis(cyclopentadienyl) derivatives of transition metalsand methods for their preparation are disclosed in U.S. Pat. No.5,384,299 (corresponding to EP-A-277,004) and U.S. application Ser. No.459,921, filed Jan. 2, 1990, now abandoned (corresponding toWO-91/09882), which are incorporated herein by reference.

Suitable tri-cyclopentadienyl or substituted cyclopentadienyl transitionmetal compounds include those containing a bridging group linking twocyclopentadienyl groups and those without such bridging groups.

Suitable unbridged tri-cyclopentadienyl transition metal derivatives arerepresented by the following formula (XVI):Cp₃MX_(n″)  (XVI)wherein Cp, M and X are as defined for formula (VI) and n″ is three lessthan the formal oxidation state of M and is 0 or 1, preferably 1.Preferred ligand groups X are hydrocarbyl, hydrocarbyloxy, hydride,halo, silyl, germyl, amide, and siloxy.

According to one preferred embodiment, the solid (or supported) catalystcomprises:

a supported catalyst component comprising (a) a support material, and anorganometal compound wherein the metal is selected from Groups 2–13 ofthe Periodic Table of the Elements, germanium, tin, and lead, and (b) anactivator compound comprising (b-1) a cation which is capable ofreacting with a transition metal compound to form a catalytically activetransition metal complex, and (b-2) a compatible anion having up to 100nonhydrogen atoms and containing at least one substituent comprising anactive hydrogen moiety; and

a transition metal compound.

The support material is typically treated with the organometal compound.Suitable organometal compounds are those comprising metals of Groups2–13, germanium, tin, and lead, and at least two substituents selectedfrom hydride, hydrocarbyl radicals, trihydrocarbyl silyl radicals, andtrihydrocarbyl germyl radicals. Additional substituents preferablycomprise one or more substituents selected from hydride, hydrocarbylradicals. trihydrocarbyl substituted silyl radicals, trihydrocarbylsubstituted germyt radicals, and hydrocarbyl-, trihydrocarbyl silyl- ortrihydrocarbyl germyl-substituted metalloid radicals.

The recitation “metalloid”. as used herein, includes non-metals such asboron, phosphorus which exhibit semi-metallic characteristics.

Examples of such organometal compounds include organomagnesium,organozinc, organoboron, organoaluminum, organogermanium, organotin, andorganolead compounds, and mixtures thereof. Further suitable organometalcompounds are alumoxanes. Preferred examples are alumoxanes andcompounds represented by the following formulae: MgR¹ ₂, ZnR¹ ₂, BR¹_(x)R² _(y), AlR¹ _(x)R² _(y), wherein R¹ independently each occurrenceis hydride, a hydrocarbyl radical, a trihydrocarbyl silyl radical, atrihydrocarbyl germyl radical, or a trihydrocarbyl-, trihydrocarbylsilyl-, or trihydrocarbyl germyl-substituted metalloid radical, R²independently is the same as R¹. x is 2 or 3, y is 0 or 1 and the sum ofx and y is 3, and mixtures thereof. Examples of suitable hydrocarbylmoieties are those having from 1 to 20 carbon atoms in the hydrocarbylportion thereof, such as alkyl, aryl, alkaryl, or aralkyl. Preferredradicals include methyl, ethyl, n- or i-propyl, n-, s- or t-butyl,phenyl, and benzyl. Preferably, the aluminum component is selected fromthe group consisting of alumoxane and aluminum compounds of the formulaAlR¹ _(x) wherein R¹ in each occurrence independently is hydride or ahydrocarbyl radical having from 1 to 20 carbon atoms, and x is 3.Suitable trihydrocarbyl aluminum compounds are trialkyl or triarylaluminum compounds wherein each alkyl or aryl group has from 1 to 10carbon atoms, or mixtures thereof, and preferably trialkyl aluminumcompounds such as trimethyl, triethyl, tri-isobutyl aluminum.

Alumoxanes (also referred to as aluminoxanes) are oligomeric orpolymeric aluminum oxy compounds containing chains of alternatingaluminum and oxygen atoms, whereby the aluminum carries a substituent,preferably an alkyl group. The structure of alumoxane is believed to berepresented by the following general formulae (—Al(R)—O)_(m), for acyclic alumoxane, and R₂Al—O(—Al(R)—O)_(m)—AlR₂, for a linear compound,wherein R independently in each occurrence is a C₁–C₁₀ hydrocarbyl,preferably alkyl, or halide and m is an integer ranging from 1 to 50,preferably at least 4. Alumoxanes are typically the reaction products ofwater and an aluminum alkyl, which in addition to an alkyl group maycontain halide or alkoxide groups. Reacting several different aluminumalkyl compounds, such as, for example, trimethyl aluminum andtri-isobutyl aluminum, with water yields so-called modified or mixedalumoxanes. Preferred alumoxanes are methylalumoxane and methylalumoxanemodified with minor amounts of other lower alkyl groups such asisobutyl. Alumoxanes generally contain minor to substantial amounts ofstarting aluminum alkyl compound.

The way in which the alumoxane is prepared is not critical. Whenprepared by the reaction between water and aluminum alkyl, the water maybe combined with the aluminum alkyl in various forms, such as liquid,vapor, or solid, for example in the form of crystallization water.Particular techniques for the preparation of alumoxane type compounds bycontacting an aluminum alkyl compound with an inorganic salt containingwater of crystallization are disclosed in U.S. Pat. No. 4,542,199. In aparticular preferred embodiment an aluminum alkyl compound is contactedwith a regeneratable water-containing substance such as hydratedalumina, silica or other substance. This is disclosed in European PatentApplication No. 338,044.

The supported catalyst according to this embodiment generally comprisesa support material combined or treated with the organometal compound andcontaining at least 0.1 micromol of organometal compound per g ofsupport material, typically at least 5 micromole per g support material,advantageously at least 0.5 weight percent of the metal, preferablyaluminum, expressed in gram of metal atoms per g of support material.Preferably, the amount of metal is at least 2 weight percent, andgenerally not more than 40 weight percent, and more preferably not morethan 30 weight percent. At too high amounts of metal the supportedcatalyst becomes expensive. At too low amounts the catalyst efficiencygoes down to drop below acceptable levels.

The supported catalysts preferably contains a treated support material(a) comprising a support material and an alumoxane wherein not more than10 percent aluminum present in the treated support material isextractable in a one hour extraction with toluene of 90° C. using about10 mL toluene per gram of pretreated support material. More preferably,not more than 9 percent aluminum present in the supported catalystcomponent is extractable, and most preferably not more than 8 percent.This is especially advantageous when the supported catalyst is used in apolymerization process where a diluent or solvent is used which mayextract non-fixed alumoxane from the support material. It has been foundthat when the amount of extractables is below the levels given above,the amount of alumoxane that can diffuse into the polymerization solventor diluent, if used, is so low that no appreciable amount of polymerwill be formed in the diluent, as compared to polymer formed on thesupport material. If too much polymer is formed in the diluent thepolymer bulk density will decrease below acceptable levels and reactorfouling problems may occur.

The toluene extraction test is carried out as follows: About 1 g ofsupported catalyst component or supported catalyst, with a knownaluminum content, is added to 10 mL toluene and the mixture is thenheated to 90° C. under an inert atmosphere. The suspension is stirredwell at this temperature for 1 hour. Then the suspension is filteredapplying reduced pressure to assist in the filtration step. The solidsare washed twice with about 3 to 5 mL toluene of 90° C. per gram ofsolids. The solids are then dried at 120° C. for 1 hour, andsubsequently the aluminum content of the solids is measured. Thedifference between the initial aluminum content and the aluminum contentafter the extraction divided by the initial aluminum content andmultiplied by 100%, gives the amount of extractable aluminum.

The aluminum content can be determined by slurrying about 0.5 g ofsupported catalyst component or supported catalyst in 10 mL hexane. Theslurry is treated with 10 to 15 mL 6N sulfuric acid, followed byaddition of a known excess of EDTA. The excess amount of EDTA is thenback-titrated with zinc chloride.

Without wishing to be bound by any theory, it is believed that theactivator compound according to this embodiment reacts with theorganometal compound through the active hydrogen-containing substituent.It is believed that a group R¹ of the organometal compound combines withthe active hydrogen moiety of the activator compound to release aneutral organic compound, for example an alkane, or hydrogen gas therebychemically coupling the metal atom with the activator compound residue.Thus the activator is believed to become chemically attached to thesupport material once the support material has been treated with theorganometal compound or adduct of organometal compound and activatorcompound. Upon addition of the transition metal compound a supportedcatalyst is formed having improved properties.

The activator compound useful in the present invention contains acompatible anion having up to 100, and preferably up to 50 nonhydrogenatoms and having at least one substituent comprising an active hydrogenmoiety. Preferred substituents comprising an active hydrogen moietycorrespond to the formula (XVII):G_(q)(T-H)_(r)  (XVII):wherein G is a polyvalent hydrocarbon radical, T is O, S, NR, or PR,wherein R is a hydrocarbyl radical, a trihydrocarbyl silyl radical, atrihydrocarbyl germyl radical, or hydrogen, q is 0 or 1, and preferably1, and r is an integer from 1 to 3, preferably 1. Polyvalent hydrocarbonradical G has r+1 valencies, one valency being with a metal or metalloidof the Groups 5–15 of the Periodic Table of the Elements in thecompatible anion, the other valency or valencies of G being attached tor groups T-H. Preferred examples of G include divalent hydrocarbonradicals such as: alkylene, arylene, aralkylene, or alkarylene radicalscontaining from 1 to 20 carbon atoms, more preferably from 2 to 12carbon atoms. Suitable examples of G include phenylene, biphenylene,naphthylene, methylene, ethylene, 1,3-propylene, 1,4-butylene,phenylmethylene (—C₆H₄—CH₂—). The polyvalent hydrocarbyl portion G maybe further substituted with radicals that do not interfere with thecoupling function of the active hydrogen moiety. Preferred examples ofsuch non-interfering substituents are alkyl, aryl, alkyl- oraryl-substituted silyl and germyl radicals, and fluoro substituents.

The group T-H in the previous formula thus may be an —OH, —SH, —NRH, or—PRH group, wherein R preferably is a C₁₋₁₈, preferably a C₁₋₁₀hydrocarbyl radical or hydrogen, and H is hydrogen. Preferred R groupsare alkyls, cycloalkyls, aryls, arylalkyls, or alkylaryls of 1 to 18carbon atoms. more preferably those of 1 to 12 carbon atoms. The —OH,—SH, —NRH, or —PRH groups may be part of a larger functionality such as,for example, C(O)—OH, C(S)—SH, C(O)—NRH, and C(O)—PRH. Most preferably,the group T-H is a hydroxy group, —OH, or an amino group, —NRH.

Very preferred substituents G_(q)(T-H)_(r) comprising an active hydrogenmoiety include hydroxy- and amino-substituted aryl, aralkyl, alkaryl oralkyl groups, and most preferred are the hydroxyphenyls, especially the3- and 4-hydroxyphenyl groups, hydroxytolyls, hydroxy benzyls(hydroxymethyiphenyl), hydroxybiphenyls, hydroxynaphthyls,hydroxycyclohexyls, hydroxymethyls, and hydroxypropyls, and thecorresponding amino-substituted groups, especially those substitutedwith —NRH wherein R is an alkyl or aryl radical having from 1 to 10carbon atoms, such as for example methyl, ethyl, propyl, i-propyl, n-,i-, or t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl, phenyl,benzyl, tolyl, xylyl, naphthyl, and biphenyl.

The compatible anion containing the substituent which contains an activehydrogen moiety, may further comprise a single Group 5–15 element or aplurality of Group 5–15 elements, but is preferably a singlecoordination complex comprising a charge-bearing metal or metalloidcore, which anion is bulky. A compatible anion specifically refers to ananion which when functioning as a charge balancing anion in the catalystsystem of this invention, does not transfer an anionic substituent orfragment thereof to the transition metal cation thereby forming aneutral transition metal compound and a neutral metal by-product.“Compatible anions” are anions which are not degraded to neutrality whenthe initially formed complex decomposes and are noninterfering withdesired subsequent polymerizations.

Preferred anions are those containing a single coordination complexcomprising a charge-bearing metal or metalloid core carrying asubstituent containing an active hydrogen moiety which anion isrelatively large (bulky), capable of stabilizing the active catalystspecies (the transition metal cation) which is formed when the activatorcompound and transition metal compound are combined and said anion willbe sufficiently labile to be displaced by olefinic, diolefinic andacetylenically unsaturated compounds or other neutral Lewis bases suchas ethers, nitrites. Suitable metals for the anions of activatorcompounds include, but are not limited to, aluminum, gold, platinum.Suitable metalloids include, but are not limited to, boron, phosphorus,silicon Activator compounds which contain anions comprising acoordination complex containing a single boron atom and a substituentcomprising an active hydrogen moiety are preferred.

Preferably, compatible anions containing a substituent comprising anactive hydrogen moiety may be represented by the following generalformula (XVIII):[M′^(m+)Q_(n)(G_(q)(T-H)_(r))_(z)]^(d−)  (XVIII)wherein:

-   -   M′ is a metal or metalloid selected from Groups 5–15 of the        Periodic Table of the Elements;    -   Q independently in each occurrence is selected from the group        consisting of hydride, dihydrocarbylamido, preferably        dialkylamido, halide, hydrocarbyloxide, preferably alkoxide and        aryloxide, hydrocarbyl, and substituted-hydrocarbyl radicals,        including halo-substituted hydrocarbyl radicals, and        hydrocarbyl- and halohydrocarbyl-substituted organo-metalloid        radicals, the hydrocarbyl portion having from 1 to 20 carbons        with the proviso that in not more than one occurrence is Q        halide;    -   G is a polyvalent, having r+1 valencies and preferably divalent        hydrocarbon radical bonded to M′ and T;    -   T is O, S, NR, or PR, wherein R is a hydrocarbon radical, a        trihydrocarbyl silyl radical, a trihydrocarbyl germyl radical,        or hydrogen:    -   m is an integer from 1 to 7, preferably 3;    -   n is an integer from 0 to 7, preferably 3;    -   q is an integer 0 or 1, preferably 1;    -   r is an integer from 1 to 3, preferably 1;    -   z is an integer from 1 to 8, preferably 1;    -   d is an integer from 1 to 7, preferably 1; and    -   n+z−m=d.

Preferred boron-containing anions which are particularly useful in thisinvention may be represented by the following general formula (XIX):[BQ_(4-z′)(G_(q)(T-H)_(r))_(z′)]^(d−)  (XIX)wherein:

-   -   B is boron in a valence state of 3;    -   z′ is an integer from 1–4, preferably 1;    -   d is 1; and    -   Q, G, T. H, q, and r are as defined for formula (XVIII).        Preferably, z′ is 1, q is 1, and r is 1.

Illustrative, but not limiting, examples of anions of activatorcompounds to be used in the present invention are boron-containinganions such as triphenyl(hydroxyphenyl)borate,diphenyl-di(hydroxyphenyl)borate, triphenyl(2,4-dihydroxyphenyl)borate,tri(p-tolyl)(hydroxyphenyl)borate,tris-(pentafluorophenyl)(hydroxyphenyl)borate,tris-(2,4-dimethylphenyl)(hydroxyphenyl)borate,tris-(3,5-dimethylphenyl)(hydroxyphenyl)borate,tris-(3,5-di-trifluoromethylphenyl)(hydroxyphenyl)borate,tris(pentafluorophenyl)(2-hydroxyethyl)borate,tris(pentafluorophenyl)(4-hydroxybutyl)borate,tris(pentafluorophenyl)(4-hydroxycyclohexyl)borate,tris(pentafluorophenyl)(4-(4′-hydroxyphenyl)phenyl)borate,tris(pentafluorophenyl)(6-hydroxy-2-naphthyl)borate. A highly preferredactivator complex is tris(pentafluorophenyl)(4-hydroxyphenyl)borate.Other preferred anions of activator compounds are those above mentionedborates wherein the hydroxy functionality is replaced by an amino NHRfunctionality wherein R preferably is methyl, ethyl, or t-butyl.

The cationic portion (b-1) of the activator compound to be used inassociation with the compatible anion (b-2) can be any cation which iscapable of reacting with the transition metal compound to form acatalytically active transition metal complex, especially a cationictransition metal complex. The cations (b-1) and the anions (b-2) areused in such ratios as to give a neutral activator compound. Preferablythe cation is selected from the group consisting of Brønsted acidiccations, carbonium cations, silylium cations, and cationic oxidizingagents.

Brønsted acidic cations may be represented by the following generalformula:(L-H)⁺wherein:

L is a neutral Lewis base, preferably a nitrogen, phosphorus, or sulfurcontaining Lewis base; and (L-H)⁺ is a Brønsted acid. The Brønstedacidic cations are believed to react with the transition metal compoundby transfer of a proton of said cation, which proton combines with oneof the ligands on the transition metal compound to release a neutralcompound.

Illustrative, but not limiting, examples of Brønsted acidic cations ofactivator compounds to be used in the present invention aretrialkyl-substituted ammonium cations such as triethylammonium,tripropylammonium, tri(n-butyl)ammonium, trimethylammonium,tributylammonium, and tri(n-octyl)ammonium. Also suitable areN,N-dialkyl anilinium cations such as N,N-dimethyanilinium.N,N-diethylanilinium, N,N-2,4,6-pentamethylanilinium,N,N-dimethylbenzylammonium; dialkylamrnmonium cations such asdi-(i-propyl)ammonium, dicyclohexylammonium; and triarylphosphoniumcations such as triphenylphosphonium, tri(methylphenyl)phosphonium,tri(dimethylphenyl)phosphonium, dimethylsulphonium, diethylsulphonium,and diphenylsulphonium.

A second type of suitable cation corresponds to the formula:{circle around (C)}⁺wherein {circle around (C)}⁺ is a stable carbonium or silylium ioncontaining up to 30 nonhydrogen atoms, the cation being capable ofreacting with a substituent of the transition metal compound andconverting it into a catalytically active transition metal complex,especially a cationic transition metal complex. Suitable examples ofcations include tropyllium, triphenylmethylium. benzene(diazonium).Silylium salts have been previously generically disclosed in J. Chem.Soc. Chem. Comm., 1993, 383–384, as well as Lambert, J. B. et, al.,Organometallics. 1994, 13, 2430–2443. Preferred silylium cations aretriethylsilylium, and trimethylsilylium and ether substituted adductsthereof.

Another suitable type of cation comprises a cationic oxidizing agentreprente by the formula:Ox^(e+)wherein Ox^(e+) is a cationic oxidizing agent having a charge of e+, ande is an integer from 1 to 3.

Examples of cationic oxidizing agents include: ferrocenium,hydrocarbyl-substituted ferrocenium, Ag⁺, and Pb²⁺.

The quantity of activator compound in the supported catalyst componentand the supported catalyst is not critical, but typically ranges from0.1, preferably from 1 to 2,000 micromoles of activator compound pergram of treated support material. Preferably, the supported catalyst orcomponent contains from 10 to 1,000 micromoles of activator compound pergram of treated support material.

Generally, the ratio of moles of activator compound (b) to gramatoms oftransition metal in compound (c) in the supported catalyst is from0.05:1 to 100:1, preferably from 0.5:1 to 20:1 and most preferably from1:1 to 5:1 mole activator compound per gramatom of transition metal inthe transition metal compound. At too low ratios the supported catalystwill not be very active, whereas at too high ratios the catalyst becomesless economic due to the relatively high cost associated with the use oflarge quantities of activator compound.

The supported catalyst according to this embodiment can be prepared bycombining the support material with the organometal compound and theactivator compound. The order of addition is not critical. Theorganometal compound may be either first combined with the supportmaterial or with the activator compound, and subsequently the activatorcompound or the support material may be added. One preferred embodimentcomprises treating the support material first with the organometalcompound by combining the organometal compound in a suitable solvent,such as a hydrocarbon solvent, with the support material. Thetemperature, pressure, and contact time for this treatment are notcritical, but generally vary from −20° C. to 150° C., fromsubatmospheric to 10 bar, more preferably at atmospheric pressure, for 5minutes to 48 hours. Usually the slurry is agitated. After thistreatment the solids are typically separated from the solvent. Anyexcess of organometal compound could then be removed by techniques knownin the art. This method is especially suitable for obtaining supportmaterial with relatively low metal loadings.

According to a preferred embodiment, the support material is firstsubjected to a thermal treatment at 100° C. to 1000° C. preferably at200° C. to 850° C. Typically, this treatment is carried out for 10minutes to 72 hours. preferably from 0.5 hours to 24 hours. Then thethermally treated support material is combined with the organometalcompound, preferably AlR′₃ wherein R′ has the meaning definedhereinbefore in a suitable diluent or solvent, preferably one in whichthe organometal compound is soluble. Typical solvents are hydrocarbonsolvents having from 5 to 12 carbon atoms, preferably aromatic solventssuch as toluene and xylenes, or aliphatic solvents of 6 to 10 carbonatoms, such as hexane, heptane, octane, nonane, decane, and isomersthereof, cycloaliphatic solvents of 6 to 12 carbon atoms such ascyclohexane, or mixtures of any of these.

The support material is combined with the organometal compound at atemperature of −20° C. to 150° C., preferably at 20° C. to 100° C. Thecontact time is not critical and can vary from 5 minutes to 72 hours,and is preferably from 0.5 hours to 36 hours. Agitation is preferablyapplied. The thus treated support material is then preferably contactedwith the activator compound.

An alternative treatment of the support material, suitable for obtainingalumoxane loadings attached to the support material, involves one orboth of the following steps A and B:

-   A. heating a support material containing alumoxane under an inert    atmosphere for a period and at a temperature sufficient to fix    alumoxane to the support material;-   B. subjecting the support material containing alumoxane to one or    more wash steps to remove alumoxane not fixed to the support    material;-   thereby selecting the conditions in heating step A and washing step    B so as to form a treated support material wherein not more than 10    percent aluminum present in the treated support material cis    extractable in a one hour extraction with toluene of 90° C. using    about 10 mL toluene per gram of supported catalyst component. High    amounts of alumoxane attached to the support material are obtained    using first heating step A., optionally followed by wash step B.

In this process the alumoxane treated support material may be obtainedby combining in a diluent an alumoxane with a support materialcontaining from zero to not more than 20 weight percent of water,preferably from zero to not more than 6 weight percent of water, basedon the total weight of support material and water. The alumoxanedesirably is used in a dissolved form.

Alternatively, the alumoxane pretreated support material may be obtainedby combining in a diluent, a support material containing from 0.5 to 50weight percent water, preferably from 1 to 20 weight percent water,based on the total weight of support material and water, with a compoundof the formula R″_(n*)AlX″_(3-n*) wherein R″ in independently eachoccurrence is a hydrocarbyl radical. X″ is halogen or hydrocarbyloxy,and n* is an integer from 1 to 3. Preferably, n* is 3. R″ inindependently each occurrence is preferably an alkyl radical,advantageously one containing from 1 to 12 carbon atoms. Preferred alkylradicals are methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl,tert-butyl, pentyl, iso-pentyl, hexyl, iso-hexyl, heptyl, octyl, andcyclohexyl. Highly preferred compounds of formula R″_(n)*AlX″_(3-n)* aretrimethylaluminum, triethylaluminum and tri-isobutylaluminum. When thealumoxane is prepared in situ by reacting the compound of the formulaR″_(n)*AlX″_(3-n*) with water, the mole ratio of R″_(n*)AlX″_(3-n*) towater is typically 10:1 to 1:1, preferably from 5:1 to 1:1.

The support material is added to the alumoxane or compound of theformula R″_(n*)AlX″_(3-n*), preferably dissolved in a solvent, mostpreferably a hydrocarbon solvent, or the solution of alumoxane orcompound of the formula R″_(n*)AlX″_(3-n*) is added to the supportmaterial. The support material can be used as such in dry form orslurried in a hydrocarbon diluent. Both aliphatic and aromatichydrocarbons can be used. Suitable aliphatic hydrocarbons include, forexample, pentane, isopentane, hexane, heptane, octane, iso-octane,nonane, isononane, decane cyclohexane, methylcyclohexane andcombinations of two or more of such diluents. Suitable examples ofaromatic diluents are benzene, toluene, xylene, and other alkyl orhalogen-substituted aromatic compounds. Most preferably, the diluent isan aromatic hydrocarbon, especially toluene. Suitable concentrations ofsolid support in the hydrocarbon medium range from 0.1 to 15, preferablyfrom 0.5 to 10, more preferably from 1 to 7 weight percent. The contacttime and temperature are not critical. Preferably the temperature isfrom 0° C. to 60° C., more preferably from 10° C. to 40° C. The contacttime is from 15 minutes to 40 hours, preferably from 1 to 20 hours.

Before subjecting the alumoxane-treated support material to the heatingstep or washing step, the diluent or solvent is preferably removed toobtain a free flowing powder. This is preferably done by applying atechnique which only removes the liquid and leaves the aluminumcompounds on the solid, such as by applying heat, reduced pressure,evaporation, or a combination thereof. If desired, the removal ofdiluent can be combined with the heating step, although care should betaken that the diluent is removed gradually.

The heating step and/or the washing step are conducted in such a waythat a very large proportion (more than about 90 percent by weight) ofthe alumoxane which remains on the support material is fixed.Preferably, a heating step is used, more preferably a heating step isused followed by a washing step. When used in the preferred combinationboth steps cooperate such that in the heating step the alumoxane isfixed to the support material, whereas in the washing step the alumoxanewhich is not fixed is removed to a substantial degree. The uppertemperature for the heat-treatment is preferably below the temperatureat which the support material begins to agglomerate and form lumps whichare difficult to redisperse, and below the alumoxane decompositiontemperature. When the transition metal compound c) is added before theheat treatment, the heating temperature should be below thedecomposition temperature of the transition metal compound. Preferably,the to heat-treatment is carried out at a temperature from 90° C. to250° C. for a period from 15 minutes to 24 hours. More preferably, theheat treatment is carried out at a temperature from 160° C. to 200° C.for a period from 30 minutes to 4 hours. Good results have been obtainedwhile heating for 8 hours at 100° C. as well as while heating for 2hours at 175° C. By means of preliminary experiments, a person skilledin the art will be able to define the heat-treatment conditions thatwill provide the desired result. It is also noted, that the longer theheat treatment takes, the higher the amount of alumoxane fixed to thesupport material will be. The heat-treatment is carried out at reducedpressure or under an inert atmosphere, such as nitrogen gas, or both butpreferably at reduced pressure. Depending on the conditions in theheating step, the alumoxane may be fixed to the support material to sucha high degree that a wash step may be omitted.

In the wash step, the number of washes and the solvent used are suchthat sufficient amounts of non-fixed alumoxane are removed. The washingconditions should be such that non-fixed alumoxane is soluble in thewash solvent. The support material containing alumoxane, preferablyalready subjected to a heat-treatment, is preferably subjected to one tofive wash steps using an aromatic hydrocarbon solvent at a temperaturefrom 0° C. to 110° C. More preferably, the temperature is from 20° C. to100° C. Preferred examples of aromatic solvents include toluene, benzeneand xylenes. More preferably, the aromatic hydrocarbon solvent istoluene. At the end of the wash treatment, the solvent is removed by atechnique that also removes the alumoxane dissolved in the solvent, suchas by filtration or decantation. Preferably, the wash solvent is removedto provide a free flowing powder.

The organometal compound treated support material is then typicallyreslurried in a suitable diluent and combined with the activatorcompound. The activator compound is preferably used in a diluent.Suitable diluents include hydrocarbon and halogenated hydrocarbondiluents. Any type of solvent or diluent can be used which does notreact with the catalyst components in such a way as to negatively impactthe catalytic properties. Preferred diluents are aromatic hydrocarbons,such as toluene, benzene, and xylenes, and aliphatic hydrocarbons suchas hexane, heptane, and cyclohexane. Preferred halogenated hydrocarbonsinclude methylene chloride and carbon tetrachloride. The temperature isnot critical but generally varies between −20° C. and the decompositiontemperature of the activator. Typical contact times varv from a fewminutes to several days. Agitation of the reaction mixture is preferred.Advantageously, the activator compound is dissolved, using heat toassist in dissolution where desired. It may be desirable to carry outthe contacting between the organometal-treated support material and theactivator compound at elevated temperatures. Preferably, such elevatedtemperatures are from 45° C. to 120° C.

Instead of first treating the support material with the organometalcompound, preferably aluminum component, and subsequently adding theactivator compound, the organometal compound, preferably aluminumcomponent, and activator compound may be combined in a suitable diluentprior to adding or combining the reaction mixture to or with the supportmaterial.

Without wishing to be bound by any theory, it is believed that an organogroup of the organometal compound reacts with the active hydrogen moietycontained in the activator anion (b-2) to form a reaction or contactproduct (hereinafter also referred to as “adduct”). For example. Whenthe organometal compound is trialkylaluminum AlR₃ and the activehydrogen-containing moiety is represented by G-OH, the reaction productis believed to comprise G-O—AlR₂ whereas further an alkane by-product RHis formed. This adduct G-O—AlR₂ when combined with the support materialcontaining hydroxyl groups, Si—OH in case of a silica support material,is believed to form Si—O—Al(R)—O-G together with alkane RH asby-product. This method of preparing the supported catalyst componenthas been found to run very smoothly and to provide catalysts andcatalyst precursors or components having desirable properties. Typicalratios to be used in this reaction are from 1:1 to 20:1 moles oforganometal compound to mole equivalents of active hydrogen moietiescontained in the activator anion (b-2).

The amount of adduct, formed by combining the organometal compound withthe activator compound, to be combined with the support material is notcritical. Preferably, the amount is not higher than can be fixed to thesupport material. Typically, this is determined by the amount of supportmaterial hydroxyls. The amount of adduct to be employed is preferablynot more than the equivalent amount of such hydroxyl groups. Less thanthe equivalent amount is preferably used, more preferably the ratiobetween moles of adduct to moles of surface reactive groups such ashydroxyls is between 0.01 and 1, even more preferably between 0.02 and0.8. Prior to adding the transition metal compound it is preferred,especially when less than an equivalent amount of adduct is added withrespect to surface reactive groups, to add an additional amount oforganometal compound to the reaction product of support material and theadduct to remove any remaining surface reactive groups which otherwisemay react with the transition metal and thus require higher amountsthereof to achieve equal catalytic activity. Prior to combining it withthe transition metal compound, the supported catalyst component can bewashed, if desired, to remove any excess-of adduct or organometalcompound.

The supported catalyst component comprising the support material.organometal compound, and the activator may be isolated to obtain a freeflowing powder by removing the liquid medium using preferably filtrationor evaporation techniques.

Although the transition metal compound may be combined with theactivator compound, or the adduct of the organometal compound and theactivator compound, prior to combining the activator compound or itsadduct with the support material, this results in reduced catalystefficiencies. Preferably, the transition metal is first combined withthe support material treated with the organometal component and beforeadding the activator compound, or the transition metal is added afterthe treated support material and activator have been combined, or afterthe activator adduct and the support material have been combined. Mostpreferably, the transition metal compound (c) is added to the reactionproduct of the support material treated with the organometal compoundand activator compound, or after the activator adduct and the supportmaterial have been combined.

The transition metal compound is preferably used dissolved in a suitablesolvent, such as a hydrocarbon solvent, advantageously a C₅₋₁₀ aliphaticor cycloaliphatic hydrocarbon or a C₆₋₁₀ aromatic hydrocarbon. Thecontact temperature is not critical provided it is below thedecomposition temperature of the transition metal and of the activator.Good results are obtained in a temperature range of 0° C. to 100° C. Allsteps in the present process should be conducted in the absence ofoxygen and moisture.

Upon combining the transition metal compound with the supported catalystcomponent, the supernatant liquid typically is colorless indicating thatthe transition metal compound, which solution typically is colored,substantially remains with the solid supported catalyst.

According to an alternative preferred embodiment the solid (orsupported) catalyst comprises:

a supported catalyst component comprising a support material and analumoxane wherein not more than 10 percent aluminum present in thesupported catalyst component is extractable in a one hour extractionwith toluene of 90° C. using 10 ml toluene per gram of supportedcatalyst component;

and a transition metal compound.

This solid catalyst according to this embodiment may be used in theabsence of the activator compound (b) comprising (b-1) a cation which iscapable of reacting with a transition metal compound to form acatalytically active transition metal complex, and (b-2) a compatibleanion having up to 100 nonhydrogen atoms and containing at least onesubstituent comprising an active hydrogen moiety.

According to this alternative embodiment, the aluminum atom (from thealumoxane component) to transition metal atom mole ratio in thesupported catalyst generally is from 1 to 5000, preferably from 25 to1000 and most preferably from 50 to 500.

The quantity of transition metal compound in the supported catalyst ofthe present invention is not critical, but typically ranges from 0.1 to1000 micromoles of transition metal compound per gram of supportmaterial. Preferably, the supported catalyst contains from 1 to 250micromoles of transition metal compound per gram of support material.

The supported catalyst according to this embodiment is obtainable byheating and/or washing a support material containing alumoxane under aninert atmosphere for a period and at a temperature sufficient to fixalumoxane to the support material, as discussed above.

It may be advantageous to use in the present process the solid catalystin association with impurity scavengers which serve to protect the solidcatalyst from catalyst poisons such as water, oxygen, and polarcompounds. Preferred compounds for this purpose include anorganoaluminum compound represented by the following formula:RnAlX_(3-n)wherein R is a C₁–C₂₀ hydrocarbyl group; X is a halogen atom or a C₁–C₂₀hydrocarbyloxy group; and n is a positive integer selected from 1 to 3,or an organoaluminumoxy compound represented by the following formula:

-   -   wherein R is a C₁–C₂₀ hydrocarbyl group; and n is a positive        integer selected from 5 to 50.

By the treatment with the organoaluminum compound or theorganoaluminumoxy compound, the resistance of the solid catalyst systemto impurities, such as water, oxygen which are present in the solidcatalyst system, can be improved, and the solid catalyst system can bestored for a prolonged period of time.

In the above treatment, the organoaluminum compound or theorganoaluminumoxy compound is used preferably in an amount of 0.1 to 100mol in terms of aluminum, more preferably in an amount of 1 to 30 mol,per mol of a transition metal compound contained in the solid catalystsystem. It is noted that the organoaluminiumoxy compound shouldpreferably not be used in amount that may cause desorption of thetransition metal compound from the solid catalyst.

The solid catalyst system to be used in the method of the presentinvention can be stored in the form of a slurry thereof in an inerthydrocarbon solvent, or dried and stored in a solid form thereof.

When a copolymerization reaction for producing the ethylene copolymer ofthe present invention is conducted using the solid catalyst system, itis important that the copolymerization reaction be performed underconditions. such that the reaction rate is limited by independentdiffusion of each of the polymerization participants (such as hydrogen,ethylene and at least one comonomer) into the ethylene copolymer beingformed. For this purpose, the copolymerization reaction must beconducted under conditions such that the ethylene copolymer being formedaround the solid catalyst system is not melted or dissolved in thereaction system.

For realizing the above-mentioned polymerization reaction conditions,the copolymerization reaction is conducted by slurry polymerization.

By conducting slurry polymerization under the above-mentioned reactionconditions, as long as the reaction conditions are appropriatelycontrolled, the ethylene copolymer being formed around the solidcatalyst system is not melted or dissolved during the polymerizationreaction, but maintains a powdery form (which powdery form is achievedby the use of the above-mentioned specific catalyst system) during thereaction, so that one of the above-mentioned requirements for enablingthe polymerization reaction to proceed at a diffusion-limited rate, suchthat the produced copolymer must not be melted in the reaction mixturebut maintains the solid state, can be satisfied.

When a copolymerization reaction is conducted by slurry polymerization,a polymerization pressure is generally from 1 to 100 atm, preferablyfrom 3 to 30 atm, and a polymerization temperature is generally from 20to 115° C., preferably from 50 to 105° C. However, the upper limit ofthe polymerization temperature is a temperature which is highest amongtemperatures at which the ethylene copolymer produced can maintain tosubstantially a powdery state. Such a highest temperature variesdepending on the density of the ethylene copolymer produced and the typeof a solvent used.

As a solvent to be used for slurry polymerization, the inert solvents,which are mentioned above in connection with the preparation of thesolid catalyst system, can be suitably used. Especially, isobutane,isopentane, heptane, hexane and octane are preferred.

As mentioned above, in the present invention, it is important that theethylene copolymer produced must maintain a powdery state during thepolymerization reaction. Therefore, the upper limit of thepolymerization temperature is extremely important.

In the method of the present invention, as mentioned above, ethylene iscopolymerized with at least one comonomer. Typical reactors for thepolymerization can include slurry loop reactors or autoclaves.

As mentioned above, at least one comonomer to be used in the method ofthe present invention is selected from the group comprising a compoundrepresented by the formula H₂C═CHR wherein R is a C₁–C₂₀ linear,branched or cyclic alkyl group or a C₆–C₂₀ aryl group, and a C₄–C₂₀linear, branched or cyclic diene. Illustrative examples of the compoundsrepresented by the formula H₂C═CHR include propylene, 1-butene,1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene,1-tetradecene. 1-hexadecene, 1-octadecene. 1-eicosene, vinylcyclohexeneand styrene. Illustrative examples of C₄–C₂₀ linear, branched and cyclicdienes include 1,3-butadiene, 1,4-pentadiene, 1,5-hexadiene,1,4-hexadiene and cyclohexadiene. Of these, propylene, 1-butene,1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene,1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene are especiallypreferred.

In producing the ethylene copolymer, the molecular weight of theethylene copolymer produced can be controlled by changing the content ofhydrogen in the reaction system or by changing the polymerizationtemperature, as described in DE 3127133.2.

In the present invention, the solid catalyst system may contain, inaddition to the above-mentioned components, various additives which areknown to be useful for the ethylene copolymerization.

The present invention also relates to blend compositions comprising saidnovel ethylene copolymer and:

a) a second ethylene copolymer of the present invention of differentmolecular weight or density; or

b) a homogeneous narrow composition distribution ethylene/α-olefininterpolymer;

c) a heterogeneous broad distribution ethylene/α-olefin interpolymer; or

d) a homopolymer (prepared by a catalyst component other than that usedto prepare the ethylene copolymer of the present invention); or

e) a combination of any two or more of a), b) c) or d).

When used as the first component (Component I) in all the foregoingblend compositions of the present invention with a second component(Component II), the ethylene copolymer has the following properties:

The amount of the first ethylene copolymer incorporated into the blendedcomposition of the present invention is from 1 to 99, preferably from 10to 90, more preferably from 25 to 75, and most preferably from 35 to 65percent, by weight based on the combined weights of components I and II.

The density of the first ethylene copolymer incorporated into theblended composition of the present invention is generally from generallyfrom 0.870 to 0.980, preferably from 0.890 to 0.965, more preferablyfrom 0.915 to 0.955 g/cm³.

The melt index (I₂) for the first ethylene copolymer incorporated intothe blended composition of the present invention is generally from0.0001 to 10000, preferably from 0.001 to 5000, more preferably from0.01 to 3000 g/10 min.

The I_(21.6)/I₂ ratio of the first ethylene copolymer incorporated intothe blended composition of the present invention is from 15 to 65,preferably from 18 to 55, more preferably is from 20 to 50 or the I₁₀/I₂ratio is from 5 to 30, preferably from 5 to 28, more preferably is from5.5 to 25.

The M_(w)/M_(n) ratio of the first ethylene copolymer incorporated intothe blended composition of the present invention is from 2.5 to 10,preferably from 2.8 to 8, and more preferably from 3 to 7.

Blends compositions comprising the ethylene copolymer with a secondethylene copolymer of the present invention of different molecularweight or density, are another aspect of the present invention. As longas the method of the present invention is essentially applied to theproduction of an ethylene copolymer, any of a method in which one ormore different ethylene copolymers of this invention and each havingexcellent ESCR properties and different comonomer contents areseparately produced using this method and blended by means of a kneader(hereinafter, frequently referred to as “blending-and-kneading method”)and a method in which an ethylene copolymer comprising a mixture of twoor more different ethylene copolymer components having differentcomonomer contents is produced by multi-stage polymerization or using aplurality of different types of catalysts to be used in the presentinvention, can be very advantageously utilized. Further, an ethylenecopolymer comprised of a mixture of two or more different ethylenecopolymer components having different comonomer contents can be producedby using a plurality of different types of catalysts to be used in thepresent invention, not only can the impact resistance and ESCRproperties be further improved, but also a markedly improved balance ofvarious properties, such as impact resistance, rigidity, melt-flowcharacteristics, can be achieved.

The amount of the second ethylene copolymer of the present invention,incorporated into the blended composition of the present invention isfrom 1 to 99, preferably from 10 to 90, more preferably from 25 to 75,and most preferably from 35 to 65 percent, by weight based on thecombined weights of Components I and II.

The density of the second ethylene copolymer incorporated into theblended composition of the present invention is generally from generallyfrom 0.915 to 0.985, preferably from 0.935 to 0.983, more preferablyfrom 0.955 to 0.980, and most preferably from 0.960 to 0.978 g/cm³.

The melt index (I₂) for the second ethylene copolymer incorporated intothe blended composition of the present invention is generally from0.0001 to 10000, preferably from 0.001 to 5000, more preferably from0.01 to 3000, most preferably from 10 to 1000 g/10 min.

The I₁₀/I₂ ratio of the second ethylene copolymer incorporated into theblended composition of the present invention is from 5 to 30, preferablyfrom 5.3 to 28, more preferably is from 5.5 to 25 or the I_(21.6)/I₂ratio of the second ethylene copolymer incorporated into the blendedcomposition of the present invention is from 15 to 55, preferably from18 to 55, more preferably is from 20 to 50, most preferably from 22 to35.

The M_(w)/M_(n) ratio of the second ethylene copolymer incorporated intothe blended composition of the present invention is from 2.5 to 10,preferably from 2.8 to 8, and more preferably from 3 to 7.

Blends compositions comprising the ethylene copolymer with homogeneousnarrow composition interpolymers, most preferably the substantiallylinear ethylene/α-olefin interpolymers are another aspect of the presentinvention. The homogeneous interpolymer components of the blendcompositions are herein defined as defined in U.S. Pat. No. 3,645,992(Elston), the disclosure of which is incorporated herein by reference.Accordingly, homogeneous interpolymers are those in which the comonomeris randomly distributed within a given interpolymer molecule and whereinsubstantially all of the interpolymer molecules have the sameethylenelcomonomer ratio within that interpolymer. Such interpolymersare distinct from the typical Ziegler catalyzed interpolymers which areknown as heterogeneous interpolymers and are those in which theinterpolymer molecules do not have the same ethylene/comonomer ratio.The homogeneous polymers are also distinct from LDPE produced by highpressure free radical catalyzed ethylene polymerization which results inhighly branched polyethylene which is known to those skilled in the artto have numerous long chain branches.

The term “narrow composition distribution” used herein describes thecomonomer distribution for homogeneous interpolymers and means that thehomogeneous interpolymers have only a single melting peak as measured byDifferential Scanning Calorimetry (DSC) and essentially lack ameasurable “linear” polymer fraction.

The narrow composition distribution homogeneous interpolymers can alsobe characterized by their SCBDI (Short Chain Branch Distribution Index)or CDBI (Composition Distribution Branch Index) which is defined as theweight percent of the polymer molecules having a comonomer contentwithin 50 percent of the median total molar comonomer content. The CDBIof a polymer is readily calculated from data obtained from techniquesknown in the art, such as, for example, temperature rising elutionfractionation (abbreviated herein as “TREF”) as described, for example,in Wild et al. Journal of Polymer Science, Poly. Phys. Ed. Vol. 20. p.441 (1982), in U.S. Pat. No. 4,798,081 (Hazlitt et al.). or as isdescribed in U.S. Pat. No. 5,008,204 (Stehling), the disclosure of whichis incorporated herein by reference. The technique for calculating CDBIis described in U.S. Pat. No. 5,322,728 (Davey et al.) and in U.S. Pat.No. 5,246,783 (Spenadel et al.) or in U.S. Pat. No. 5,089,321 (Chum etal.) the disclosures of all of which are incorporated herein byreference. The SCBDI or CDBI for the homogeneous narrow compositionethylene/α-olefin interpolymers used in the present invention ispreferably greater than 50 percent, especially greater than 70 percent,most preferably greater than 90%.

The narrow composition distribution homogeneous interpolymer blendcomponents of this invention essentially lack a measurable “highdensity” (or homopoLymer) fraction as measured by the TREF technique.The homogeneous interpolymers and polymers have a degree of branchingless than or equal to 2 methyls/1000 carbons in 15 percent (by weight)or less, preferably less than 10 percent (by weight), and especiallyless than 5 percent (by weight).

Preferred components of the blends of the current invention are thesubstantially linear ethylene/α-olefin interpolymers. The substantiallylinear ethylene/α-olefin interpolymers are herein defined as in U.S.Pat. Nos. 5.272,236 and 5,278,272 by Lai et al (U.S. Pat. Nos. 5,272.236and 5,278,272), the teachings of which contained therein, are hereinincorporated in their entirety by reference.

-   -   The substantially linear ethylene/α-olefin interpolymers are        also homogeneous interpolymers as the comonomer is randomly        distributed within a given interpolymer molecule and        substantially all of the interpolymer molecules have the same        ethylene/comonomer ratio within that interpolymer.

However the term “substantially linear” ethylene/α-olefin interpolymermeans that the polymer also contains long chain branching. As a resultof the constrained geometry of the catalyst, the substantially linearethylene interpolymers can contain long chain branching, which, as inLDPE, can greatly improve the processability (as measured by theprocessing index (PI), or onset of melt fracture, or shear thinningcapability) compared with other polymers of about the same I₂ andM_(w)/M_(n). Long chain branching is defined herein as a chain length ofat least one carbon more than two carbons less than the total number ofcarbons in the comonomer, for example, the long chain branch of anethyleneloctene substantially linear ethylene interpolymer is at leastseven (7) carbons in length (that is, 8 carbons less 2 equals 6 carbonsplus one equals seven carbons long chain branch length). The long chainbranch can be as long as about the same length as the length of thepolymer back-bone. Long chain branching is determined by using ¹³Cnuclear magnetic resonance (NMR) spectroscopy and is quantified usingthe method of Randall (Rev. Macromol. Chem. Phys., C29 (2&3), p.285–297), the disclosure of which is incorporated herein by reference.Long chain branching, of course, is to be distinguished from short chainbranches which result solely from incorporation of the comonomer, so forexample the short chain branch of an ethylene/octene substantiallylinear polymer is six carbons in length, while the long chain branch forthat same polymer is at least seven carbons in length.

More specifically, the polymer backbone of a substantially linearethylene/α-olefin interpolymer is substituted with 0.01 long chainbranches/1000 carbons to 3 long chain branches/1000 carbons, morepreferably from 0.01 long chain branches/1000 carbons to 1 long chainbranches/1000 carbons, and especially from 0.05 long chain branches/1000carbons to 1 long chain branches/1000 carbons.

The substantially linear ethylene/α-olefin interpolymers useful in thisinvention surprisingly have excellent processability, even though theyhave relatively narrow molecular weight distributions. The substantiallylinear ethylene/α-olefin interpolymers have a molecular weightdistribution, M_(w)/M_(n), defined by the equation:M _(w) /M _(n)≦(I ₁₀ /I ₂)−4.63.

Even more surprising, the melt flow ratio (I₁₀/I₂) of the substantiallylinear ethylene/α-olefin interpolymers can be varied essentiallyindependently of the polydispersity index (that is, molecular weightdistribution (M_(w)/M_(n))). This is contrasted with conventionalheterogeneously branched linear polyethylene resins having theologicalproperties such that as the polydispersity index increases, the I₁₀/I₂value also increases.

For the substantially linear ethylene/α-olefin polymers used in thecompositions of the invention, the I₁₀/I₂ ratio indicates the degree oflong chain branching, that is, the higher the I₁₀/I₂ ratio, the morelong chain branching in the polymer.

The “theological processing index” (PI) is the apparent viscosity (inkpoise) of a polymer measured by a gas extrusion rheometer (GER). Thegas extrusion rheometer is described by M. Shida, R. N. Shroff and L. V.Cancio in Polymer Engineering Science, Vol. 17, no. 11, p. 770 (1977),and in “Rheometers for Molten Plastics” by John Dealy, published by VanNostrand Reinhold Co. (1982) on page 97–99, both publications of whichare incorporated by reference herein in their entirety. All GERexperiments are performed at a temperature of 190° C., at nitrogenpressures between 5250 to 500 psig using a 0.0296 inch diameter, 20:1L/D die with an entrance angle of 180°. For the substantially linearethylene/α-olefin polymers described herein, the PI is the apparentviscosity (in kpoise) of a material measured by GER at an apparent shearstress of 2.15×10⁶ dyne/cm². The substantially linear ethylene/a-olefininterpolymers described herein preferably have a PI in the range of 0.01kpoise to 50 kpoise, preferably 15 kpoise or less. The substantiallylinear ethylene/α-olefin polymers described herein have a PI less thanor equal to 70 percent of the PI of a comparative linearethylene/a-olefin polymer which does not contain long chain branchingbut of about the same I₂ and M_(w)/M_(n).

An apparent shear stress vs, apparent shear rate plot is used toidentify the melt fracture phenomena. According to Ramamurthy in Journalof Rheology 30(2), 337–357, 1986, above a certain critical flow rate,the observed extrudate irregularities may be broadly classified into twomain types: surface melt fracture and gross melt fracture.

Surface melt fracture occurs under apparently steady flow conditions andranges in detail from loss of specular gloss to the more severe form of“sharkskin”. In this disclosure, the onset of surface melt fracture(OSMF) is characterized at the beginning of losing extrudate gloss atwhich the surface roughness of extrudate can only be detected by 40×magnification. The critical shear rate at onset of surface melt fracturefor the substantially linear ethylene/α-olefin interpolymers is at least50 percent greater than the critical shear rate at the onset of surfacemelt fracture of a linear ethylene/a-olefin polymer which does notcontain long chain branching but of about the same I₂ and M_(w)/M_(n),wherein “about the same” as used herein means that each value is within10 percent of the comparative value of the comparative linear ethylenepolymer.

Gross melt fracture occurs at unsteady flow conditions and ranges indetail from regular (alternating rough and smooth, helical, etc.) torandom distortions. For commercial acceptability, (for example, in blownfilm products), surface defects should be minimal, if not absent. Thecritical shear rate at onset of surface melt fracture (OSMF) and onsetof gross melt fracture (OGMF) will be used herein based on the changesof surface roughness and configurations of the extrudates extruded by aGER.

The homogeneous interpolymer component of the blend is preferably, aninterpolymer of ethylene with at least one comonomer selected from thegroup comprising compounds represented by the formula H₂C═CHR wherein Ris a C₁–C₁₈ linear, branched or cyclic alkyl group or a C₆–C₂₀ arylgroup, and a C₄–C₂₀ linear, branched or cyclic diene. Illustrativeexamples of the compounds represented by the formula H₂C═CHR includepropylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene,1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene,1-eicosene, vinylcyclohexene and styrene. Illustrative examples ofC₄–C₂₀ linear, branched and cyclic dienes include 1,3-butadiene,1,4-pentadiene, 1,5-hexadiene, 1,4-hexadiene and cyclo hexadiene. Ofthese, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene,1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene,1-octadecene and 1-eicosene are especially preferred.

The amount of the homogeneous narrow composition distributionethylene/α-olefin interpolymer incorporated into the blended compositionof the present invention is from 1 to 99, preferably from 10 to 90, morepreferably from 25 to 75, and most preferably from 35 to 65 percent, byweight based on the combined weights of components I and II.

The density of the homogeneous narrow composition distributionethylene/α-olefin interpolymer incorporated into the blended compositionof the present invention is generally from generally from 0.915 to0.985, preferably from 0.935 to 0.983, more preferably from 0.955 to0.980 g/cm³.

The melt index (I₂) for the homogeneous narrow composition distributionethylene/α-olefin interpolymer incorporated into the blended compositionof the present invention is generally from 0.0001 to 10000. preferablyfrom 0.001 to 5000, more preferably from 0.01 to 3000 g/10 min

The I₁₀/I₂ ratio of the homogeneous narrow composition distributionethylene/α-olefin interpolymer incorporated into the blended compositionof the present invention is from 5 to 25, preferably from 5.3 to 25,more preferably is from 5.5 to 20, or the I_(21.6)/I₂ ratio of thehomogeneous narrow composition distribution ethylene/α-olefininterpolymer incorporated into the blended composition of the presentinvention is from 10 to 50, preferably from 12 to 45, more preferably isfrom 15 to 40.

The M_(w)/M_(n) ratio of the homogeneous narrow composition distributionethylene/α-olefin interpolymer incorporated into the blended compositionof the present invention (including the substantially linearethylene/α-olefin interpolymer) is less than 3.

The homogeneous narrow composition distribution ethylene/α-olefininterpolymer component may be prepared using the previously describedtransition metal catalysts. Preparation of the homogeneous narrowcomposition distribution, substantially linear ethylene/α-olefinpolymers requires the use of the previously described transition metalcompounds and constrained geometry single site catalysts. The activatingcocatalysts and activating techniques have been previously taught withrespect to different metal complexes, in the following references:European Patent EP-A-277,003; U.S. Pat. No. 5,153,157; U.S. Pat. No.5,064,802; European Patents EP-A-468,651 and EP-A-520,732 (equivalent toU.S. Ser. No. 07/876,268 filed May 5, 1992, now U.S. Pat. No. 5,721,185and U.S. Pat. No. 5,350,723; the teachings of which are herebyincorporated by reference.

Suitable activating cocatalysts useful in combination with the singlesite catalyst component are those compounds capable of abstraction of anX substituent therefrom to form an inert, noninterfering counter ion, orthat form a zwitterionic derivative of the catalyst component. Suitableactivating cocatalysts for use herein include perfluorinatedtri(aryl)boron compounds, and most especiallytris(pentafluoro-phenyl)borane; nonpolymeric, compatible,noncoordinating, ion forming compounds (including the use of suchcompounds under oxidizing conditions), especially the use of ammonium-,phosphonium-, oxonium-, carbonium-, silylium- or sulfonium-salts ofcompatible, noncoordinating anions, and ferrocenium salts of compatible,noncoordinating anions. Suitable activating techniques include the useof bulk electrolysis. A combination of the foregoing activatingcocatalysts and techniques may be employed as well.

More particularly, suitable ion forming compounds useful as cocatalysts.comprise a cation which is a Brønsted acid capable of donating a proton,and a compatible, noncoordinating anion. A⁻. As used herein, the term“noncoordinating” means an anion or substance which either does notcoordinate to the Group 4 metal containing precursor complex and thecatalytic derivative derived therefrom, or which is only weaklycoordinated to such complexes thereby remaining sufficiently labile tobe displaced by a neutral Lewis base. “Compatible anions” are anionswhich are not degraded to neutrality when the initially formed complexdecomposes and are noninterfering with desired subsequent polymerizationor other uses of the complex.

Preferred anions are those containing a single coordination complexcomprising a charge-bearing metal or metalloid core which anion iscapable of balancing the charge of the active catalyst species (themetal cation) which may be formed when the two components are combined.Also, said anion should be sufficiently labile to be displaced byolefinic, diolefinic and acetylenically unsaturated compounds or otherneutral Lewis bases such as ethers or nitriles. Suitable metals include,but are not limited to, aluminum, gold and platinum. Suitable metalloidsinclude, but are not limited to, boron, phosphorus, and silicon.Compounds containing anions which comprise coordination complexescontaining a single metal or metalloid atom are, of course, well knownand many, particularly such compounds containing a single boron atom inthe anion portion, are available commercially.

Preferably such cocatalysts may be represented by the following generalformula:(L*-H)⁺ _(d)(A)^(d−).wherein:

L* is a neutral Lewis base;

(L*-H)⁻ is a Bronsted acid;

A^(d−) is a noncoordinating, compatible anion having a charge of d−, and

d is an integer from 1 to 3.

More preferably A^(d−) corresponds to the formula: [M′Q₄]⁻;

wherein:

M′ is boron or aluminum in the +3 formal oxidation state; and

Q independently each occurrence is selected from hydride, dialkylamido,halide, hydrocarbyl, hydrocarbyloxide, halosubstituted-hydrocarbyl,halosubstituted hydrocarbyloxy, and halo-substituted silylhydrocarbylradicals (including perhalogenated hydrocarbyl-perhalogenatedhydrocarbyloxy- and perhalogenated silylhydrocarbyl radicals), said Qhaving up to 20 carbons with the proviso that in not more than oneoccurrence is Q halide. Examples of suitable hydrocarbyloxide Q groupsare disclosed in U.S. Pat. No. 5,296,433, the teachings of which areherein incorporated by reference.

In a more preferred example, d is one, that is, the counter ion has asingle negative charge and is A⁻. Activating cocatalysts comprisingboron which are particularly useful in the preparation of catalysts ofthis invention may be represented by the following general formula:(L*-H)⁺(BQ₄)⁻;wherein:

L* is as previously defined;

B is boron in a formal oxidation state of 3; and

Q is a hydrocarbyl-, hydrocarbyloxy-, fluorinated hydrocarbyl-,fluorinated hydrocarbyloxy-, or fluorinated silylhydrocarbyl-group of upto 20 nonhydrogen atoms, with the proviso that in not more than oneoccasion is Q hydrocarbyl.

Most preferably, Q is each occurrence a fluorinated aryl group,especially, a pentafluorophenyl group.

Illustrative, but not limiting, examples of boron compounds which may beused as an activating cocatalyst for the present invention aretri-substituted ammonium salts such as:

-   trimethylammoniumtetrakis(pentafluorophenyl)borate,-   triethylammoniumtetrakis(pentafluorophenyl)borate,-   tripropylammoniumtetrakis(pentafluorophenyl)borate,-   tri(n-butyl)ammoniumtetrakis(pentafluorophenyl)borate,-   tri(sec-butyl)ammoniumtetrakis(pentafluorophenyl)borate,-   N,N-dimethyl-N-dodecylammoniumtetrakis(pentafluorophenyl)borate,-   N,N-dimethyl-N-octadecylammoniumtetrakis(pentafluorophenyl)borate,-   N-methyl-N,N-didodecylammoniumtetrakis(pentafluorophenyl)borate,-   N-methyl-N,N-dioctadecylammoniumtetrakis(pentafluorophenyl)borate,-   N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate,-   N,N-dimethylanilinium n-butyltris(pentafluorophenyl)borate,-   N,N-dimethylanilinium benzyltris(pentafluorophenyl)borate,-   N,N-dimethylaniliniumtetrakis(4-(t-butyldimethylsilyl)-2,3,5,6-tetrafluorophenyl)borate,-   N,N-dimethylaniliniumtetrakis(4-(triisopropylsilyl)-2,3,5,6-tetrafluorophenyl)borate,-   N,N-dimethylanilinium    pentafluorophenoxytris(pentafluorophenyl)borate,-   N,N-diethylaniliniumtetrakis(pentafluorophenyl)borate,-   N,N-dimethyl-2,4,6-trimethylaniliniumtetrakis(pentafluorophenyl)borate,-   trimethylammoniumtetrakis(2,3,4,6-tetrafluorophenyl)borate,-   triethylammoniumtetrakis(2,3,4,6-tetrafluorophenyl)borate,-   tripropylammoniumtetrakis(2,3,4,6-tetrafluorophenyl)borate,-   tri(n-butyl)ammoniumtetrakis(2,3,4,6-tetrafluorophenyl)borate,-   dimethyl(t-butyl)ammoniumtetrakis(2,3,4,6-tetrafluorophenyl)borate,-   N,N-dimethylaniliniumtetrakis(2,3,4,6-tetrafluorophenyl)borate,-   N,N-diethylaniliniumtetrakis(2,3,4,6-tetrafluorophenyl)borate, and-   N,N-dimethyl-2,4,6-trimethyaniliniumtetrakis(2,3,4,6-tetrafluorophenyl)borate;    disubstituted ammonium salts such as:-   di-(i-propyl)ammoniumtetrakis(pentafluorophenyl)borate, and-   dicyclohexylammoniumtetrakis(pentafluorophenyl)borate;    trisubstituted phosphonium salts such as:-   triphenylphosphoniumtetrakis(pentafluorophenyl)borate,-   tri(o-tolyl)phosphoniumtetrakis(pentafluorophenyl)borate, and-   tri(2,6-dimethylphenyl)phosphoniumtetrakis(pentafluorophenyl)borate;    disubstituted oxonium salts such as:-   diphenyloxoniumtetrakis(pentafluorophenyl)borate,-   di(o-tolyl)oxoniumtetrakis(pentafluorophenyl)borate, and-   di(2,6-dimethylphenyl)oxoniumtetrakis(pentafluorophenyl)borate;    disubstituted sulfonium salts such as:-   diphenylsulfoniumtetrakis(pentafluorophenyl)borate,-   di(o-tolyl)sulfoniumtetrakis(pentafluorophenyl)borate, and-   bis(2,6-dimethylphenyl)sulfoniumtetrakis(pentafluorophenyl)borate.

Preferred (L*-H)⁺ cations are N,N-dimethylanilinium, tributylammonium,N-methyl-N,N-didodecylammonium, N-methyl-N,N-dioctadecylammonium, andmixtures thereof.

Another suitable ion forming, activating cocatalyst comprises a salt ofa cationic oxidizing agent and a noncoordinating, compatible anionrepresented by the formula:(Ox^(e+))_(d)(A^(d−))_(e).wherein Ox^(e−), A^(d−) and d are as previously defined.

Examples of cationic oxidizing agents include: ferrocenium,hydrocarbyl-substituted ferrocenium, Ag⁺, or Pb⁻². Preferred embodimentsof A^(d−) are those anions previously defined with respect to theBronsted acid containing activating cocatalysts, especiallytetrakis(pentafluorophenyl)borate.

Another suitable ion forming, activating cocatalyst comprises a compoundwhich is a salt of a carbenium ion and a noncoordinating, compatibleanion represented by the formula:{circle around (C)}⁺A⁻wherein:

{circle around (C)}⁺ and A⁻ are as previously defined. A preferredcarbenium ion is the trityl cation, that is triphenylmethylium.

A further suitable ion forming, activating cocatalyst comprises acompound which is a salt of a silylium ion and a noncoordinating,compatible anion represented by the formula:R₃*Si⁺A⁻wherein:

R* is C₁₋₁₀ hydrocarbyl, and A⁻ are as previously defined.

Preferred silylium salt activating cocatalysts are trimethylsilyliumtetrakispentafluorophenylborate, triethylsilyliumtetrakispentafluorophenylborate and ether substituted adducts thereof.The use of the above silylium salts as activating cocatalysts foraddition polymerization catalysts is claimed in U.S. Ser. No.08/304,314, filed Sep. 12, 1994, now U.S. Pat. No. 5,625,087.

Certain complexes of alcohols, mercaptans, silanols, and oximes withtris(pentafluorophenyl)borane are also effective catalyst activators andmay be used for the present invention. Such cocatalysts are disclosed inU.S. Pat. No. 5,296,433, the teachings of which are herein incorporatedby reference.

The most preferred activating cocatalysts aretrispentafluorophenvlborane and N,N-dioctadecyl-N-methylammoniumtetrakispentafluorophenylborate. The latter compound being the principalcomponent of a mixture of borate salts derived from bis(hydrogenatedtallow)methylammonium compounds, which mixture may be used as theactivating cocatalyst herein.

The molar ratio of metal complex: activating cocatalyst employedpreferably ranges from 1:10 to 2:1, more preferably from 1:5 to 1.5:1,most preferably from 1:5 to 1:1.

Other activators include the previously described aluminoxanes.Preferred aluminoxanes include methylaluminoxane, propylaluminoxane,isobutylaluminoxane, combinations thereof. So-called modifiedmethylaluminoxane (MMAO) is also suitable for use as a cocatalyst. Onetechnique for preparing such modified alumoxane is disclosed in U.S.Pat. No. 4,960,878 (Crapo et al.), the disclosure of which isincorporated herein by reference. Aluminoxanes can also be made asdisclosed in U.S. Pat. No. 4,544,762 (Kaminsky et al.); U.S. Pat. No.5,015,749 (Schmidt et al.); U.S. Pat. No. 5,041,583 (Sangokoya); U.S.Pat. No. 5,041,584 (Crapo et al.); and U.S. Pat. No. 5,041,585(Deavenport et al.), the disclosures of all of which are incorporatedherein by reference. When aluminoxanes are used as the activatingcocatalyst, the molar ratio of transition metal complex: aluminumpreferably ranges from 1:2,000 to 2:1, more preferably from 1:1,000 to1.5:1, most preferably from 1:500 to 1:1.

In general, the polymerization may be accomplished at conditions wellknown in the prior art for Ziegler-Natta or Kaminsky-Sinn typepolymerization reactions, that is, temperatures from 0–250° C.,preferably 30 to 200° C. and pressures from atmospheric to 30,000atmospheres or higher. Suspension, solution, slurry, gas phase, solidstate powder polymerization or other process condition may be employedif desired. A solid component (other than that used to prepare thecatalysts used to make the ethylene homopolymer of the presentinvention), may be employed especially silica, alumina, or a polymer(especially poly(tetrafluoroethylene) or a polyolefin), and desirably isemployed when the catalysts are used in a gas phase polymerizationprocess. The support is preferably employed in an amount to provide aweight ratio of catalyst (based on metal): support from 1:100,000 to1:10, more preferably from 1:50,000 to 1:20, and most preferably from1:10,000 to 1:30.

In most polymerization reactions the molar ratio ofcatalyst:polymerizable compounds employed is from 10⁻¹²:1 to 10⁻¹:1,more preferably from 10⁻⁹:1 to 10⁻⁵:1.

Suitable solvents for polymerization are inert liquids. Examples includestraight and branched-chain hydrocarbons such as isobutane, butane,pentane, hexane, heptane, octane, and mixtures thereof; cyclic andalicyclic hydrocarbons such as cyclohexane, cycloheptane,methylcyclohexane, methylcycloheptane, and mixtures thereof;perfluorinated hydrocarbons such as perfluorinated C₄₋₁₀ alkanes, andaromatic and alkyl-substituted aromatic compounds such as benzene,toluene, xylene, ethylbenzene. Suitable solvents also include liquidolefins which may act as monomers or comonomers including ethylene,propylene, butadiene, cyclopentene, 1-hexene, 1-hexane,4-vinylcyclohexene, vinylcyclohexane, 3-methyl-1-pentene,4-methyl-1-pentene, 1,4-hexadiene, 1-octene, 1-decene, styrene,divinylbenzene, allylbenzene, vinyltoluene (including all isomers aloneor in admixture). Mixtures of the foregoing are also suitable.

Blends compositions comprising the ethylene copolymer with theheterogeneous broad composition distribution ethylene interpolymers areanother aspect of the present invention. Included in the definition ofheterogeneous interpolymers as used herein are those produced usingZiegler catalysts and also those produced by the chromium-basedsilica-supported systems, commonly known as the Phillips-type catalysts.

The term heterogeneous describes interpolymers in which the interpolymermolecules do not have the same ethylene/comonomer ratio. The term “broadcomposition distribution” used herein describes the comonomerdistribution for heterogeneous interpolymers and means that theheterogeneous interpolymers have a “linear” fraction and that theheterogeneous interpolymers have multiple melting peaks (that is,exhibit at least two distinct melting peaks) by DSC. The heterogeneousinterpolymers and polymers have a degree of branching less than or equalto 2 methyls/1000 carbons in 10 percent (by weight) or more, preferablymore than 15 percent (by weight), and especially more than 20 percent(by weight). The heterogeneous interpolymers also have a degree ofbranching equal to or greater than 25 methyls/1000 carbons in 25 percentor less (by weight), preferably less than 15 percent (by weight), andespecially less than 10 percent (by weight).

The heterogeneous interpolymer component of the blend can also be anethylene homopolymer or an interpolymer of ethylene with at least onecomonomer selected from the group consisting of a compound representedby the formula H₂C═CHR wherein R is a C₁–C₁₈ linear, branched or cyclicalkyl group or a C₆–C₂₀ aryl group, and a C₄–C₂₀ linear, branched orcyclic diene. Illustrative examples of the compounds represented by theformula H₂C═CHR include propylene, 1-butene, 1-pentene, 1-hexene,4-methyl-1-pentene. 1-octene, 1-decene, 1-dodecene, 1-tetradecene,1-hexadecene, 1-octadecene, 1-eicosene, vinylcyclohexene and styrene.Illustrative examples of C₄–C₂₀ linear, branched and cyclic dienesinclude 1,3-butadiene, 1,4-pentadiene, 1,5-hexadiene, 1,4-hexadiene andcyclo hexadiene. Of these, propylene, 1-butene, 1-pentene, 1-hexene,4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene,1-hexadecene, 1-octadecene and 1-eicosene are especially preferred.Heterogeneous interpolymers of ethylene and 1-butene, 1-pentene,1-hexene and 1-octene are most preferred.

The amount of the heterogeneous broad composition distributionethylene/α-olefin interpolymer incorporated into the blended compositionof the present invention is from 1 to 99, preferably from 10 to 90, morepreferably from 25 to 75, and most preferably from 35 to 65 percent, byweight based on the combined weights of components I and II.

The density of the heterogeneous broad composition distributionethylene/α-olefin interpolymer incorporated into the blended compositionof the present invention is generally from generally from 0.915 to0.985. preferably from 0.935 to 0.983, more preferably from 0.955 to0.980 g/cm³.

The melt index (I₂) for the heterogeneous broad composition distributionethylene/α-olefin interpolymer incorporated into the blended compositionof the present invention is generally from 0.0001 to 10000, preferablyfrom 0.001 to 5000, more preferably from 0.011 to 3000 g/10 min

The I₁₀/I₂ ratio of the heterogeneous broad composition distributionethylene/α-olefin interpolymer or homopolymer made by the same catalystand process conditions as said interpolymer incorporated into theblended composition of the present invention is from 5 to 40, preferablyfrom 5.3 to 35 more preferably from 5.5 to 30, or the I_(21.6)/I₂ ratioof the heterogeneous broad composition distribution ethylene/α-olefininterpolymer incorporated into the blended composition of the presentinvention is from 15 to 80, preferably from 20 to 70 more preferablyfrom 25 to 60.

The M_(w)/M_(n) ratio of the heterogeneous broad compositiondistribution ethylene/α-olefin interpolymer incorporated into theblended composition of the present invention is generally from 3 to 12,preferably from 3.5 to 10, more preferably from 4 to 9.

Ziegler-Natta catalysts may be used to prepare the heterogeneouscomponent of the polymer blend. Preferred Ziegler-Natta catalystsinclude magnesium alkoxide-based catalysts, such as those taught by U.S.Pat. No. 4,526,943, U.S. Pat. No. 4,426,316, 4,661,465, U.S. Pat. No.4,783,512, and U.S. Pat. No. 4,544,647, the disclosures of each of whichare herein incorporated by reference. Such catalysts are particularlyuseful if the heterogeneous polymer component is to be prepared underslurry process conditions.

Additional examples of Ziegler-type catalysts which are particularlyuseful for preparation of the heterogeneous polymer blend component isto be prepared under the high polymerization temperatures of thesolution process, include catalysts derived from organomagnesiumcompounds, alkyl halides or aluminum halides or hydrogen chloride, and atransition metal compound. Examples of such catalysts are described inU.S. Pat No. 4,314,912 (Lowery, Jr. et al.), U.S. Pat. No. 4,547,475(Glass et al.), and U.S. Pat. No. 4,612,300 (Coleman, III), theteachings of which are incorporated herein by reference.

Particularly suitable organomagnesium compounds include, for example,hydrocarbon soluble dihydrocarbylmagnesium such as the magnesiumdialkyls and the magnesium diaryls. Exemplary suitable magnesiumdialkyls include particularly n-butyl-sec-butylmagnesium,diisopropylmagnesium, di-n-hexylmagnesium, isopropyl-n-butyl-magnesium,ethyl-n-hexylmagnesium, ethyl-n-butylmagnesium, di-n-octylmagnesium andothers wherein the alkyl has from 1 to 20 carbon atoms. Exemplarysuitable magnesium diaryls include diphenylmagnesium, dibenzylmagnesiumand ditolylmagnesium. Suitable organomagnesium compounds include alkyland aryl magnesium alkoxides and aryloxides and aryl and alkyl magnesiumhalides with the halogen-free organomagnesium compounds being moredesirable.

Among the halide sources which can be employed herein are the activenon-metallic halides, metallic halides, and hydrogen chloride.

Suitable non-metallic halides are represented by the formula R′X whereinR′ is hydrogen or an active monovalent organic radical and X is ahalogen. Particularly suitable non-metallic halides include, forexample, hydrogen halides and active organic halides such as t-alkylhalides, allyl halides, benzyl halides and other active hydrocarbylhalides wherein hydrocarbyl is as defined hereinbefore. By an activeorganic halide is meant a hydrocarbyl halide that contains a labilehalogen at least as active, that is , as easily lost to anothercompound, as the halogen of sec-butyl chloride, preferably as active ast-butyl chloride. In addition to the organic monohalides, it isunderstood that organic dihalides, trihalides and other polyhalides thatare active as defined herein before are also suitably employed. Examplesof preferred active non-metallic halides include hydrogen chloride,hydrogen bromide, t-butyl chloride, t-amyl bromide, allyl chloride,benzyl chloride, crotyl chloride, methylvinyl carbinyl chloride,a-phenylethyl bromide, diphenyl methyl chloride . Most preferred arehydrogen chloride, t-butyl chloride, allyl chloride and benzyl chloride.

Suitable metallic halides which can be employed herein include thoserepresented by the formula MR_(y-a)X_(a) wherein:

M is a metal of Groups IIB, IIIA or IVA of Mendeleev's Periodic Table ofElements,

R is a monovalent organic radical,

X is a halogen,

Y has a value corresponding to the valence of M, and a has a value from1 to y.

Preferred metallic halides are aluminum halides of the formulaAlR_(3-a)X_(a) wherein:

-   -   each R is independently hydrocarbyl as hereinbefore defined such        as alkyl,    -   X is a halogen; and    -   a is a number from 1 to 3.

Most preferred are alkylaluminum halides such as ethylaluminumsesquichloride, diethylaluminum chloride, ethylaluminum dichloride, anddiethylaluminum bromide, with ethylaluminum dichloride being especiallypreferred. Alternatively, a metal halide such as aluminum trichloride ora combination of aluminum trichloride with an alkyl aluminum halide or atrialkyl aluminum compound may be suitably employed.

It is understood that the organic moieties of the aforementionedorganomagnesium, for example, R″, and the organic moieties of the halidesource, for example, R and R′, are suitably any other organic radicalprovided that they do not contain functional groups that poisonconventional Ziegler catalysts.

The magnesium halide can be preformed from the organomagnesium compoundand the halide source or it can be formed in situ in which instance thecatalvst is preferably prepared by mixing in a suitable solvent orreaction medium (1) the organomagnesium component and (2) the halidesource. followed by the other catalyst components.

Any of the conventional Ziegler-Natta transition metal compounds can beusefully employed as the transition metal component in preparing thesupported catalyst component. Typically, the transition metal componentis a compound of a Group IVB, VB, or VIB metal. The transition metalcomponent is generally, represented by the formulas:TrX′_(4-q)(OR¹)_(q), TrX′_(4-q)R² _(q), VOX′3 and VO(OR¹)₃.

Tr is a Group IVB, VB, or VIB metal, preferably a Group IVB or VB metal,preferably titanium, vanadium or zirconium,

q is 0 or a number equal to or less than 4.

X′ is a halogen, and

R¹ is an alkyl group, aryl group or cycloalkyl group having from 1 to 20carbon atoms, and

R² is an alkyl group, aryl group, aralkyl group, substituted aralkyls.The aryl, aralkyls and substituted aralkys contain 1 to 20 carbon atoms,preferably 1 to 10 carbon atoms. When the transition metal compoundcontains a hydrocarbyl group, R², being an alkyl, cycloalkyl, aryl, oraralkyl group, the hydrocarbyl group will preferably not contain an Hatom in the position beta to the metal carbon bond. Illustrative butnon-limiting examples of aralkyl groups are methyl, neo-pentyl,2,2-dimethylbutyl, 2,2-dimethylhexyl; aryl groups such as benzyl;cycloalkyl groups such as 1-norbornyl. Mixtures of these transitionmetal compounds can be employed if desired.

Illustrative examples of the transition metal compounds include TiCl₄,TiBr₄, Ti(OC₂H₅)₃Cl, Ti(OC₂H₅)Cl₃, Ti(OC₄H₉)₃Cl, Ti(OC₃H₇)₂Cl₂,Ti(OC₆H₁₃)₂Cl₂, Ti(OC₈H₁₇)₂Br₂, and Ti(OC₁₂H₂₅)Cl₃, Ti(O-i-C₃H₇)₄, andTi(O-n-C₄H₉)₄.

Illustrative examples of vanadium compounds include VCl₄, VOCl₃,VO(OC₂H₅)₃, and VO(OC₄H₉)₃.

Illustrative examples of zirconium compounds include ZrCl₄,ZrCl₃(OC₂H₅), ZrCl₂(OC₂H₅)₂, ZrCl(OC₂H₅)₃, Zr(OC₂H₅)₄, ZrCl₃(OC₄H₉),ZrCl₂(OC₄H₉)2, and ZrCl(OC₄H₉)₃.

As indicated above, mixtures of the transition metal compounds may beusefully employed, no restriction being imposed on the number oftransition metal compounds which may be contracted with the support. Anyhalogenide and alkoxide transition metal compound or mixtures thereofcan be usefully employed. The previously named transition metalcompounds are especially preferred with vanadium tetrachloride, vanadiumoxychloride, titanium tetraisopropoxide, titanium tetrabutoxide, andtitanium tetrachloride being most preferred.

Suitable Ziegler catalyst materials may also be derived from a inertoxide supports and transition metal compounds. Examples of suchcompositions suitable for use in the solution polymerization process aredescribed in U.S. Pat. No. 5,420,090 (Spencer, et al.), the teachings ofwhich are incorporated herein by reference.

The amount of the homopolymer prepared with a catalyst other than thatused to prepare the ethylene copolymer of the present inventionincorporated into the blended composition of the present invention infrom 1 to 99, preferably from 10 to 90, more preferably from 25 to 75,and most preferably from 35 to 65 percent, by weight based on thecombined weights of components I and II.

The melt index (I₂) for the homopolymer prepared with a catalyst andprocess other than that used to prepare the ethylene copolymer of thepresent invention incorporated into the blended composition of thepresent invention is generally from 0.0001 to 10000, preferably from0.001 to 5000, more preferably from 0.01 to 3000 g/10 min

The I_(21.6)/I₂ ratio of the homopolymer prepared with a catalyst andprocess other than that used to prepare the ethylene copolymer of thepresent invention incorporated into the blended composition of thepresent invention is from 15 to 80, preferably from 18 to 70 morepreferably from 20 to 60 or the I₁₀/I₂ is from 5 to 40, preferably from5.3 to 35 more preferably from 5.5 to 30.

The M_(w)/M_(n) ratio of the homopolymer prepared with a catalyst andprocess other than that used to prepare the ethylene copolymer of thepresent invention incorporated into the blended composition of thepresent invention is generally from 2.5 to 12, preferably from 2.8 to10, more preferably from 3 to 9.

If blends of the ethylene copolymer of the present invention asdescribed herein, are required with further ethylene interpolymers, eachcomponent can be made separately in different reactors, and subsequentlyblended together.

The blend compositions may also be produced via a continuous (as opposedto a batch or semi-batch operation) controlled polymerization processusing at least one reactor. Preferably, though, the ethylene copolymerof the present invention and the additional ethylene interpolymerscomponents of the blend compositions are made in a multiple reactorscheme, operated either in parallel or in series, such as thosedisclosed in U.S. Pat. No. 3,914,342 (Mitchell) and WO 94/00500, theteachings of which are hereby incorporated herein by reference. Forexample, at least two reactors operated in series, that is, one afterthe other, may be used. Alternatively, the reactors may be operated inparallel, that is, conducting the polymerization steps A and B inseparate reactors and subsequently combining melt streams to yield acomposite product blend. In the multiple reactor scheme, at least one ofthe reactors makes the ethylene copolymer of the present invention usingthe supported metallocene catalyst described herein, under slurryprocess conditions, and at least one of the reactors makes theadditional components of the blend using the required single or multiplecatalysts at polymerization temperatures, pressures and feedconcentrations required to produce the polymer with the desiredproperties.

Thus in one embodiment, the ethylene copolymer of the present inventionusing the supported metallocene catalyst described herein, is made underslurry process conditions in a first reactor in Step A and the contentsof the first reactor passed to a second reactor in which the feedconcentrations and the temperature are adjusted, to form under slurryprocess conditions in Step B a second ethylene copolymer of the presentinvention having a different molecular weight or density.

In a further embodiment, the ethylene copolymer of the present inventionusing the supported metallocene catalyst described herein, is made underslurry process conditions in a first reactor in Step A and the contentsof the first reactor passed to a second reactor in which the feedconcentrations and the temperature are adjusted, and one or more of theZiegler catalysts described herein added, to form, in Step B, underslurry process conditions, the heterogeneous ethylene interpolymer orhomopolymer component of the polymer blend with the desired properties.

In a further embodiment the ethylene copolymer of the present inventionusing the supported metallocene catalyst described herein, is made underslurry process conditions in a first reactor in Step A and the contentsof the first reactor enter a second reactor in which the feedconcentrations and temperatures are adjusted and one of the metallocenecatalysts described herein is added to form the homogeneous ethyleneinterpolymer or homopolymer component of the polymer blend with thedesired properties in Step B under solution process conditions.

In a further embodiment, the ethylene copolymer of the present inventionusing the supported metallocene catalyst described herein, is made underslurry process conditions in a first reactor in Step A and the contentsof the first reactor passed to a second reactor in which the temperatureand feed concentrations are adjusted, and one or more of the Zieglercatalysts described herein added, to form, in Step B, under solutionprocess conditions, the heterogeneous ethylene interpolymer orhomopolymer component of the polymer blend with the desired properties.

Additives such as antioxidants (for example, hindered phenolics (forexample, Irganox™ 1010), phosphites (for example, Irgafos™ 168)), clingadditives (for example, PIB), antiblock additives, pigments, fillers,can also be included in the formulations, to the extent that they do notinterfere with the enhanced formulation properties discovered byApplicants. Both Irganox™ and Irgafo™ are made by and trademarks of CibaGeigy Corporation. Irgafos™ 168 is a phosphite stabilizer and Irganox™1010 is a hindered polyphenol stabilizer (for example,tetrakis[methylene 3-(3,5-dit-butyl-4-hydroxyphenylpropionate)]-methane.

The density of the final blend compositions of the present invention isgenerally from generally from 0.870 to 0.980, preferably from 0.915 to0.975, more preferably from 0.935 to 0.970, and most preferably from0.945 to 0.968 g/cm³.

The melt index, I₂, of the final blend compositions of the presentinvention is generally from 0.0001 to 10000, preferably from 0.001 to5000, and more preferably from 0.01 to 3000 g/10 min.

The I₁₀/I₂ ratio of the final blend compositions of the presentinvention is from 5 to 100, preferably from 5 to 90 more preferably from5 to 80, or the I_(21.6)/I₂ ratio of the final blend compositions of thepresent invention is from 20 to 200, preferably from 30 to 180, morepreferably from 40 to 150, and most preferably from 50 to 130.

The M_(w)/M_(n) ratio of the final blend compositions of the presentinvention is from 2.5 to 50, preferably from 3 to 45, and morepreferably from 5 to 40.

The ethylene copolymer of the present invention has a specific comonomercontent distribution characteristic, wherein, in one aspect, the lowerthe molecular weight of a copolymer fraction in a molecular weightdistribution of an ethylene copolymer, the lower the comonomer contentof the copolymer fraction; and, in the other aspect, the higher themolecular weight of a copolymer fraction, the higher the comonomercontent of the copolymer fraction. By virtue of this comonomer contentdistribution characteristic, the ethylene copolymer of the presentinvention has excellent properties, such as high impact strength andexcellent environmental stress cracking resistance (ESCR). Further, theethylene copolymer of the present invention does not exhibit a broadtailing on both the low molecular weight side and the high molecularweight side, so that the ethylene copolymer contains substantially noimpurities such as a wax, a gel. Further, as long as the method of thepresent invention is essentially applied to the production of anethylene copolymer, any of a method in which two or more differentethylene copolymers having different comonomer contents are separatelyproduced and blended by means of a kneader, and a method in which anethylene copolymer comprising a mixture of two or more differentethylene copolymer components having different comonomer contents isproduced by multi-stage polymerization or using a plurality of differenttypes of catalysts to be used in the present invention, can be veryadvantageously utilized in a preferred mode of the method of the presentinvention. The mixture of the ethylene copolymers produced by theabove-mentioned preferred method of the present invention can have acomonomer content distribution in which the comonomer contentcontinuously varies in accordance with an increase in molecular weightof the copolymer, contrary to that of the mixture of conventionalethylene copolymers. Thus, according to the above-mentioned slurrymethod of the present invention, excellent characteristic can beobtained with respect to the comonomer content distribution of themixture of the ethylene copolymers, which has not been achieved by theprior art techniques.

Due to the above-mentioned excellent properties and characteristics, theethylene copolymer and blend compositions of the present invention canbe advantageously used for the production of blown films, cast films,laminate films blow-molded articles, injection-molded articles, pipes,coating materials for electric transmission cables

EXAMPLES

The present invention will now be further illustrated in more detailwith reference to the following Examples and Comparative Examples, whichshould not be construed as limiting the scope of the present invention.

Example 1

20 g of silica SP-9-10046 (manufactured and sold by Grace GmbH,Germany), which had been treated at 250° C. for 2 hours under vacuum,was slurried in 250 ml of toluene. To the resultant slurry was added asolution of 20 ml (0.11 mol) of triethylaluminum in 100 ml of toluene.The resultant mixture was stirred for 2 hours, filtered, washed with two100 ml portions of fresh toluene and dried under vacuum. The resultant22 g of dried mixture was slurried in 300 ml of toluene and heated to70° C. to thereby obtain a slurry. To this slurry was added a solutionof 1.25 g (1.77 mmol) of triethylammoniumtris(pentafluorophenyl)(4-hydroxyphenyl)borate in 200 ml of toluenewhich had been heated to and maintained at 70° C. for 30 minutes. Uponaddition the heating was removed and the resultant mixture was stirredfor 3 hours. After that, a 12.3 ml aliquot of a dark violet colored0.0714M solution of titanium(N-1,1-dimethylethyl)dimethyl[1-(1,2,3,4,5,-eta)-2,3,4,5-tetramethyl-2,4-cyclopentadien-1-yl]silanaminato[(2-)N]-(η⁴-1,3-pentadiene)in ISOPAR™ E (manufactured and sold by Exxon Chemical Co., USA) wasadded to the mixture and the resultant mixture was stirred for 2 hoursto thereby obtain a green colored solid catalyst system.

Isopentane, ethylene, 1-butene, hydrogen and the solid catalyst systemwere continuously fed to a 10-liter jacketed, continuously stirred tankreactor. The flow rates of isopentane, ethylene, 1-butene and hydrogenwere, respectively, 2,500 g/hr, 700 g/hr, 20 g/hr and 0.3 liter/hr. Theslurry product formed was continuously withdrawn from the reactor. Thetotal pressure of the reactor was 15 atm and the internal temperature ofthe reactor was maintained at 70° C. The slurry withdrawn was fed to aflash tank to remove the diluent and the dry, free flowing ethylenecopolymer powder was obtained.

The ethylene copolymer thus obtained had the following properties: adensity by ASTM D-792 of 0.929 g/cm³; a melt index of 0.50 g/10 minutesas measured by ASTM D-1238 at 190° C. under a load of 2.16 kg; an Mw of152,000 and an M_(w)/M_(n) of 4.5, both as measured by GPC; an Mt (apoint in molecular weight on a molecular weight distribution profile asmeasured by GPC at which the profile showed a peak having a maximumintensity) of 69,000; an approximate straight line obtained from thecomonomer content distribution profile) had a gradient of 0.0013 withinthe range of from 22,000 to 220,000 in terms of a molecular weight Mcwhich satisfies the formula log (69,000)−log(Mc)≦0.5; a temperature (atwhich a maximum amount of extraction was exhibited) of 86° C. asmeasured by CFC; in CFC an approximate straight line having a gradientof −0.053 was obtained from the relationship between an arbitrarytemperature falling within the range of between 86° C. and 96° C. and apoint on a molecular weight distribution profile of a copolymer fractionextracted at the arbitrary temperature, which point had a peak having amaximum intensity; and the total amount of copolymer fractions extractedat temperatures of 76° C. or less in CFC was 3.1 wt %.

Examples 2 and 3

25 g of silica SP-9-10046 (manufactured and sold by Grace GmbH, Germany)having a water content of 3.5% by weight was added to 508 g of 10%methylalumoxane solution in toluene (manufactured and sold by WitcoGmbH, Germany) while continuously stirring. The mixture was stirred fora further two hours and then the solvent was removed under reducedpressure at 20° C. to yield a free-flowing powder. The resultedfree-flowing powder was then heated at 175° C. for two hours undervacuum. The resulting powder was re-slurried in 700 ml of toluene andthe mixture was washed with two portions of fresh toluene at 100° C. Thesupport was then dried under vacuum at 120° C. for 1 hour. 63.9 g ofsupport was obtained having an aluminum content of 26.4% by weight.

To 60 gram of the support was added a 33.6 ml aliquot of a dark violet0.0714 M solution of titanium(N-1,1-dimethylethyl)dimethyl[1-(1,2,3,4,5-eta)-2,3,4,5-tetramethyl-2,4-cyclopentadien-1-yl]silanaminato[(2-)N]-(eta4-1,3-pentadiene) in ISOPAR™ E (manufactured and sold by EXXON ChemicalCo., USA) and the mixture stirred for several hours to yield a greencolored supported catalyst.

Substantially the same polymerization procedures as in Example 1 wererepeated, except that the flow rates of isopentane, ethylene, 1-buteneand hydrogen were changed as indicated in Table 1. The results of thereactions are shown in Table 1.

Examples 4 to 6

Substantially the same procedures were used as in Examples 2 and 3 toproduce the supported catalyst, except that a different MAO treatedsilica was used wherein the MAO was also immobilized on the silica, butusing a different method.

Substantially the same polymerization procedures as in Example 1 wereused, except that the polymerization temperatures and the flow rates ofisopentane, 1-butene and hydrogen were changed as indicated in Table 1.The gradient and CFC 1 and CFC 2 data for Examples 4–6 are extrapolates,based on density, from the results of Example 1–3.

The results of the reactions are shown in Table 1.

Example 7

6.2 g (8.8 mmol) of triethylammoniumtris(pentafluorophenyl)(4-hydroxyphenyl)borate was dissolved in 4 literof toluene which had been heated to and maintained at 90° C. for 30minutes. To this solvent was added a 40 ml aliquot of a 1M solution oftriehexylaluminum in toluene. The resultant mixture was stirred for 1min at 90° C. In a second vessel. 100 g of silica P-10 (manufactured andsold by Fuji silysia, Japan), which had been treated at 500° C. for 3hours in flowing nitrogen, was slurried in 1.7 liter of toluene. Thissilica slurry was heated to 90° C. To this silica slurry was added saidmixture of triethylammoniumtris(pentafluorophenyl)(4-hydroxyphenyl)borate and triethylaluminumwhich was at 90° C., and the resulting slurry stirred for 3 hours at 90°C. A 206 ml aliquot of a 1 M solution of trihexylaluminum in toluene wasadded. The resultant mixture in about 5.9 liter of toluene was stirredat 90° C. for 1 hour. Then the supernatant of the resultant mixture wasremoved by decantation method using 90° C. toluene to remove excesstrihexylaluminum. The decantation was repeated 5 times. After that, a 20ml aliquot of a dark violet colored 0.218M solution of titanium(N-1,1-dimethylethyl)dimethyl[1-(1,2,3,4,5,-eta)-2,3,4,5-tetramethyl-2,4-cvclopentadien-1-yl]silanaminato[(2-)N]-(η⁴-1,3-pentadiene)in ISOPAR™ E (manufactured and sold by Exxon Chemical Co., USA) wasadded to the mixture and the resultant mixture was stirred for 3 hoursto thereby obtain a green colored solid catalyst system.

Hexane, ethylene, 1-butene, hydrogen and the solid catalyst system werecontinuously fed to a continuously stirred tank reactor. The flow ratesof hexane, ethylene, and hydrogen were, respectively, 46.2 kg/hr, 0.15kg/hr, 0.15 kg/hr. The flow rates of 1-butene were 0.11 kg/hr (Example7). The slurry product formed was continuously withdrawn from thereactor. The total pressure of the reactor was 10 atm and the internaltemperature of the reactor was maintained at 80° C. The slurry withdrawnwas fed to a flash tank to remove the diluent and the dry, free flowingethylene copolymer powder was obtained. The properties of the ethylenecopolymers thus obtained are shown in Table 2.

Example 8

200 g of silica P-10 (manufactured and sold by Fuji silysia. Japan),which had been treated at 500° C. for 3 hours in flowing nitrogen, wasslurried in 5 liter of hexane. To the resultant slurry was added a 400ml aliquot of a 1 M solution of triethylaluminum in hexane. Theresultant mixture was stirred for 0.5 hour at room temperature. To thisslurry was added a solution of 20.1 g (17.6 mmol) of bis(hydrogenatedtallowalkyl)methylammoniumtris(pentafluorophenyl)(4-hydroxyphenyl)borate in 296 ml of toluene. Theresultant mixture was stirred for 0.5 hour at room temperature. Afterthat, a 60 ml aliquot of a dark violet colored 0.218M solution oftitanium(N-1,1-dimethylethyl)dimethyl[1-(1,2,3,4,5,-eta)-2,3,4,5-tetramethyl-2,4-cyclopentadien-1-yl]silanaminato[(2-)N]-(η⁴-1,3-pentadiene)in ISOPAR™ E (manufactured and sold by Exxon Chemical Co. USA) was addedto the mixture and the resultant mixture was stirred for 3 hours at roomtemperature to thereby obtain a green colored solid catalyst system.

Substantially the same polymerization procedures as in Example 7 wererepeated, except that the flow of 1-butene was changed as indicated inTable 1. The results of the reactions are shown in Table 2.

Comparative Example 1

A 1,000 ml flask was charged with 508 g of a 10% solution ofmethylaluminoxane in toluene (manufactured and sold by Witco GmbH,Germany) and then 25 g of silica SD 3216.30 silica (manufactured andsold by Grace GmbH, Germany) having a water content of about 3.5% byweight was added to the flask while continuously stirring. The resultantmixture was stirred for a further 2 hours and then the solvent wasremoved under reduced pressure at 20° C. to thereby obtain a freeflowing powder. The obtained powder was then heated at 175° C. for 2hours under vacuum. The powder was re-slurried in 700 ml of toluene. Theresultant mixture was heated and refluxed for 1 hour. The mixture wasfiltered, washed with two portions of fresh toluene at 100° C. and driedunder vacuum at 120° C. for 1 hour. As a result, 63.9 g of dried mixturehaving an aluminum content of 23.8% by weight was obtained.

A solid catalyst system was prepared by slurrying 0.5 g of theabove-obtained dried mixture in 20 ml of ISOPAR™ E (manufactured andsold by Exxon Chemical Co., USA), and after stirring for a few minutesto disperse the dried mixture, a 0.142 ml aliquot of a dark orange-browncolored solution of[(tert-butylamido)(dimethyl)(tetramethyl-η⁵-cyclopentadienyl)silanedimethyltitanium was added. The resultant mixture was stirred for a fewminutes to thereby obtain a yellow-orange colored solid catalyst system.

A stirred 3-liter reactor was charged with 1,191 ml of ISOPAR™ E(manufactured and sold by Exxon Chemical Co., USA), 309 ml of 1-octeneand 0.3 liter of hydrogen. The reactor contents were heated to 80° C.and ethylene was added to the reactor in an amount sufficient to bringthe total pressure of the reactor to about 31 atm. The solid catalystsystem containing 1.5 μmol of titanium was added to the reactor tothereby initiate a polymerization reaction. Ethylene was supplied to thereactor continuously on demand. After 21 minutes the ethylene line wasblocked and the reactor contents were dumped into a sample container.The resultant copolymer was dried overnight. As a result, 41 g of anethylene copolymer was obtained.

The ethylene copolymer thus obtained had the following properties: adensity of 0.883 g/cm³; an MFR of 0.35 g/10 minutes as measured at 190°C. under a load of 2.16 kg; an Mw of 130,000 and an M_(w)/M_(n) of 3.5,both as measured by GPC; an Mt (a point in molecular weight on amolecular weight distribution profile as measured by GPC at which theprofile showed a peak having a maximum intensity) of 96,000; anapproximate straight line obtained from the comonomer contentdistribution profile) had a gradient of 0.0030 within the range of from30,000 to 304,000 in terms of a molecular weight Mc which satisfies theformula log (96,000)−log(Mc)≦0.5; a temperature (at which a maximumamount of extraction was exhibited) of 37° C. as measured by CFC; in CFCan approximate straight line having a gradient of −0.010 was obtainedfrom the relationship between an arbitrary temperature falling withinthe range of between 37° C. and 47° C. and a point on a molecular weightdistribution profile of a copolymer fraction extracted at the arbitrarytemperature, which point had a peak having a maximum intensity; and thetotal amount of copolymer fractions extracted at temperatures of 27° C.or less in CFC was 18.5 wt %.

Comparative Example 2

A 200-ml glass flask, which had been fully purged with nitrogen gas, wascharged with 4.0 g of silica (manufactured and sold by Fuji SilysiaChemical Ltd., Japan) and 40 ml of toluene. The resultant mixture wasstirred to obtain a suspension. The obtained suspension was cooled to−10° C. To the cooled suspension was dropwise added 30 ml of a solutionof methylaluminoxane (manufactured and sold by Albemarle Corporation,USA) in toluene (Al concentration: 1 mol/liter) over 1 hour in anitrogen atmosphere, while maintaining the temperature of the suspensionat −10° C. The resultant mixture was maintained at 0° C. for 1 hour andthen at room temperature for 1 hour, in the nitrogen atmosphere.Thereafter, the temperature of the mixture was further elevated to 110°C., so that the mixture was refluxed for 3 hours, in the nitrogenatmosphere. During a series of the above operations, generation ofmethane gas from the mixture was observed. Then, the mixture was cooledto 20° C. so that a suspension of a silica having methylaluminoxanecarried thereon was obtained.

A 1.6-liter stainless autoclave, which had been fully purged withnitrogen gas, was charged with 0.8 liter of hexane and then 0.2 mmol oftriisobutylaluminum was added to the hexane in the autoclave. To theresultant mixture was added the above-obtained silica suspension in anamount of 0.3 mmol in terms of the aluminum of the methylaluminoxanecarried on the silica. Ethylene was added to the autoclave in an amountsufficient to bring the total pressure of the autoclave to 7 kg/cm²-G.The internal temperature of the autoclave was adjusted to 65° C.

A solution of bis(n-butylcyclopentadienyl)zirconium dichloride (which isknown as a metallocene) in toluene was added to the autoclave in anamount of 1.0 μmol in terms of zirconium, and the internal temperatureof the autoclave was elevated to 70° C., to thereby initiate apolymerization reaction of the ethylene. The ethylene was supplied tothe autoclave continuously on demand.

While maintaining the total pressure of the autoclave at 7 kg/cm²-G andmaintaining the internal temperature of the autoclave at 70° C., thepolymerization reaction was carried out, so that the total consumptionof ethylene became 1.5 kg/cm²-G.

After completion of the polymerization reaction, the contents in theautoclave were dumped into a stainless container containing methanol.The resultant mixture was filtered to thereby obtain a polymer. Theobtained polymer was dried at 50° C. overnight. As a result, an ethylenecopolymer was obtained.

The autoclave was opened and the inside thereof was examined. No polymeradhering to the inner wall of the autoclave was observed.

The ethylene copolymer thus obtained had the following properties: adensity of 0.926 g/cm³; an MFR of 2.1 g/10 minutes as measured at 190°C. under a load of 2.16 kg; an Mw of 88,000 and an M_(w)/M_(n) of 2.6,both as measured by GPC; an Mt (a point in molecular weight on amolecular weight distribution profile as measured by GPC at which theprofile showed a peak having a maximum intensity) of 63,000; anapproximate straight line obtained from the comonomer contentdistribution profile) had a gradient of −0.00005 within the range offrom 20.000 to 199,000 in terms of a molecular weight Mc which satisfiesthe formula log (63,000)−log(Mc)≦0.5; a temperature (at which a maximumamount of extraction was exhibited) of 85° C. as measured by CFC; in CFCan approximate straight line having a gradient of −0.006 was obtainedfrom the relationship between an arbitrary temperature falling withinthe range of between 85° C. and 95° C. and a point on a molecular weightdistribution profile of a copolymer fraction extracted at the arbitrarytemperature, which point had a peak having a maximum intensity; and thetotal amount of copolymer fractions extracted at temperatures of 75° C.or less in CFC was 10.8 wt %.

Comparative Example 3

A stirred 3-liter reactor was charged with 1,388 ml of ISOPAR™ E(manufactured and sold by Exxon Chemical Co., USA), 128 ml of 1-octeneand 0.3 liter of hydrogen. The reactor contents were heated to 130° C.and ethylene was added to the reactor in an amount sufficient to bringthe total pressure of the reactor to about 31 atm.

A solid catalyst system containing 0.625 μmol of titanium, which wasprepared in substantially the same manner as in Example 1, was added tothe reactor to thereby initiate a polymerization reaction. Ethylene wassupplied to the reactor continuously on demand. After 10 minutes theethylene line was blocked and the reactor contents were dumped into asample container. The resultant polymer was dried overnight, to therebyobtain 30 g of an ethylene copolymer.

The ethylene copolymer thus obtained had the following properties: adensity of 0.912 g/cm³; an MFR of 4.5 g/10 minutes as measured at 190°C. under a load of 2.16 kg; an Mw of 130,000 and an M_(w)/M_(n) of 2.5,both as measured by GPC; an Mt (a point in molecular weight on amolecular weight distribution profile as measured by GPC at which theprofile showed a peak having a maximum intensity) of 50,000; anapproximate straight line obtained from the comonomer contentdistribution profile) had a gradient of 0.00003 within the range of from16,000 to 158,000 in terms of a molecular weight Mc which satisfies theformula log (50,000)−log(Mc)≦0.5; a temperature (at which a maximumamount of extraction was exhibited) of 74° C. as measured by CFC; in CFCan approximate straight line having a gradient of −0.033 was obtainedfrom the relationship between an arbitrary temperature falling withinthe range of between 74° C. and 84° C. and a point on a molecular weightdistribution profile of a copolymer fraction extracted at the arbitrarytemperature, which point had a peak having a maximum intensity; and thetotal amount of copolymer fractions extracted at temperatures of 64° C.or less in CFC was 13.4 wt %.

Comparative Example 4

A commercially available ethylene copolymer, EXACT™ 3029 (manufacturedand sold by Exxon Chemical Co., USA), was analyzed. The results of theanalysis are shown in Table 2.

Comparative Example 5

A commercially available ethylene copolymer, SP 2040 (manufactured andsold by Mitsui Petrochemical Industries. Ltd., Japan), was analyzed. Theresults of the analysis are shown in Table 2.

Comparative Example 6

A commercially available ethylene copolymer. PL 1880 (manufactured andsold by The Dow Chemical Co., USA), was analyzed. The results of theanalysis are shown in Table 2.

In Table 2, the properties of the ethylene copolymer of the presentinvention, which was obtained in Example 1, are indicated together withthose of the ethylene copolymers which were individually obtained inComparative Examples 1 to 3 and those of the commercially availableethylene copolymers in Comparative Examples 4 to 6. It is apparent thatany of the ethylene copolymers in Comparative Examples 1 to 6 do nothave the properties which match those of the ethylene copolymer of thepresent invention.

Comparative Example 7

A magnesium-chloride supported Ziegler-Natta catalysts having about 2 wt% of Ti on the surface of the support was used for the polymerization.

Hexane, ethylene, 1-butene, hydrogen and the solid catalyst system werecontinuously fed to a continuously stirred tank reactor substantially asdescribed in Example 1 to produce the copolymer powder, the propertiesof which are shown in Table 2.

Examples 9–12

Substantially the same polymerization procedures as in Example 1 wereused, except that the transition metal complex used to preparecomponents 1 and 2 was[(tert-butylamido)(dimethyl)(tetramethyl-η³-cyclopentadienyl)silanedimethyltitanium and the flow rates of isopentane, 1-butene and hydrogenwere changed to produce the polymer properties for Components I and IIsummarized in Table 3. The blends were prepared in a Winkworth 2Z-blademixer. This internal mixer is equipped with two mixing blades running atdifferent rpm: the front screw rotates at 52 rpm, the rear screw at 30rpm. The working capacity is 1.2 liters.

The powders were first dry blended with 2000 ppm Irganox® B225 availablefrom Ciba Geigy. Charges of 350 g of the mixture of the desiredcomposition were then loaded and mixed for 10 minutes at 190° C. Aftermixing the polymer was removed and was milled in a Heinrich Dreher S20grinder. The ground polymer was then ready for compression molding. Theresults of the testing of the various blend compositions are shown inTable 4.

Examples 13–16

Substantially the same polymerization procedures as in Examples 7 and 8were repeated to produce the ethylene copolymers used as Component II,except that the flow ratio of hexane, ethylene, 1-butene, hydrogen wereadjusted along with the polymerization temperature. The ethylenecopolymers produced in Examples 7 and 8 were used as Component I. Thepolymer properties for Component I and Component II and the blendformulation are summarized in Table 5. The blends were prepared withusing the twin-screw extruder (PCM-45, manufactured by IKEGAI, Co.,Ltd., Japan). The screw rotates at 100–200 rpm. The screw barreltemperature was 220° C.

The powders were first dry blended with 2000 ppm Irganox® 1076 availablefrom Ciba Geigy, 600 ppm Calcium Stearate, and 1000 ppm P-EPQ® availablefrom Sando. The results of the testing of the various blend compositionsare shown in Table 6.

Comparative Examples 8–10

Substantially the same polymerization procedures as in ComparativeExamples 7 was used to produce the ethylene homopolymers used forComponent II. Also, the ethylene copolymer produced in ComparativeExamples 7 was used as Component I. The polymer properties for ComponentI and Component II and the blend formulation are summarized in Table 5.The blends were prepared using the same procedure as in Examples 13–16.The results of the testing of the various blend compositions are shownin Table 6.

Examples 9–16 show the excellent balance of properties such as impactstrength at low temperature (as measured by G_(c) at 0 and −20° C. andby Charpy Impact Strength −20° C.), processability (as measured by V at100 l/s and by I_(21.6)), and ESCR (as measured by PENT and by BendingESCR TEST) for the various blend compositions and that such balance isbest achieved by having the comonomer preferentially in the highmolecular weight component. Further, it is clear that the Example 13–16exhibit superior properties compared to those of Comparative Examples8–10.

TABLE 1 Example Example Example Example Example Example Units 1 2 3 4 56 Polymerization (° C.) 70 55 70 30 60 40 Temperature Catalyst BorateMAO MAO MAO MAO MAO Activator Isopentane (g/hr) 2500 2500 2500 2500 18003600 Flow Ethylene Flow (g/hr) 700 850 650 850 600 600 Comonomer (g/hr)20 110 30 200 30 176 Flow Hydrogen Flow (g/hr) 0.3 0.3 0.65 1 0.3 0.8Density (g/cm³) 0.929 0.910 0.935 0.887 0.934 0.890 MFR (g/10 min) 0.50.02 0.36 0.07 0.07 0.23 M_(w)/M_(n) 4.5 4.2 4.1 4.8 3.5 3.8 Gradient*¹0.0013 0.0044 0.0011 0.0098 0.0011 0.0086 CFC 1*² −0.053 −0.026 −0.061−0.015 −0.061 −0.017 CFC 2*³ (wt %) 3.1 1.7 3.8 1.1 3.8 1.3 UnitsExample 7 Example 8 Polymerization (° C.) 80 80 Temperature CatalystActivator Borate Borate Hexane Flow (kg/hr) 46.2 46.2 Ethylene Flow(kg/hr) 5.0 5.0 Comonomer Flow (kg/hr) 0.11 0.05 Hydrogen Flow (g/hr)0.15 0.15 Density (g/cm³) 0.9295 0.9378 MFR (g/10 mm) 0.012 0.013M_(w)/M_(n) 5.50 5.81 Gradient*¹ 0.0010 0.0007 CFC 1*² −0.008 0.205 CFC2*³ (wt %) 0.0 0.0 *¹Gradial means a gradient of an approximate straightline obtained from a comonomer content distribution profile. *²CFC 1means, in CFC, a gradient of an approximate straight line obtained fromthe relationship between an arbitrary temperature (falling within therange of between a first temperature at which a maximum amount ofextraction is exhibited and a second temperature which is 10° C. higherthan the first temperature) and a point on a molecular weightdistribution profile of a copolymer fraction extracted at the arbitrarytemperature at which point the molecular weight distribution profileexhibits a peak having a maximum intensity. *³CFC 2 means a percent ofthe sum of respective amounts of copolymer fractions extracted attemperatures which are at least 10° C. lower than the above mentionedfirst temperature to the total amount of copolymer fractions as measuredby CFC.

TABLE 2 Example Comparative Comparative Comparative ComparativeComparative Comparative Comparative 1 Example 1 Example 2 Example 3Example 4 Example 5 Example 6 Example 7 Density g/cm3 0.929 0.883 0.9260.912 0.910 0.912 0.905 0.930 MFR g/10 min 0.50 0.35 2.1 4.5 2.9 3.9 1.30.015 M_(w)M_(n) 4.5 3.5 2.6 2.5 2.1 4.5 2.4 7.8 Gradient*¹ 0.00130.0030 −0.00005 −0.00003 −0.0007 0.0037 −0.0013 0.0041 CFC 1*² −0.053−0.010 −0.006 −0.033 0.000 −0.016 0.000 0.005 CFC 2*³ wt. % 3.1 18.510.8 13.4 9.3 12.3 14.5 8.0 *¹Gradient means a gradient of anapproximate straight line obtained from a comonomer content distributionprofile. *²CFC 1 means, in CFC, a gradient of an approximate straightline obtained from the relationship between an arbitrary temperature(falling within the range of between a first temperature at which amaximum amount of extraction is exhibited and a second temperature whichis 10° C. higher than the first temperature) and a point on a molecularweight distribution profile of a copolymer fraction extracted at thearbitrary temperature at which point the molecular weight distributionprofile exhibits a peak having a maximum intensity. *³CFC 2 means apercent of the sum of respective amounts of copolymer fractionsextracted at temperatures which are at least 10° C. lower than the abovementioned first temperature to the total amount of copolymer fractionsas measured by CFC.

TABLE 3 Low Mw Component High Mw Component (Component II) (Component I)Example I₂ mole % density wt % in I₂ mole % density wt % in # g/10 minbutene g/cm³ blend g/10 min butene g/cm³ blend 9 25.96 1.42 0.9380 480.00872 5.96 0.9033 52 10 34.9 2.56 0.9378 48 0.01085 2.91 0.9148 52 1131.6 4.99 0.9219 48 0.00194 1.45 0.9203 52 12 19.1 6.21 0.9210 480.01085 0 0.9484 52

TABLE 4 Units Example 9 Example 10 Example 11 Example 12 Melt FlowProperties I₂ g/10 min 0.08 0.10 0.03 0.09 I₅ g/10 min 0.25 0.32 0.110.28 I₁₀ g/10 min 0.89 1.04 0.45 0.86 I_(21.6) g/10 min 4.89 5.5 2.473.83 I₁₀/I₂ 11.1 10.4 15 9.6 I_(21.6)/I₂ 19.6 17.2 22.5 13.7 I_(21.6)/I₅61.1 55 82.3 42.6 Density g/cm3 0.9241 0.9273 0.9251 0.9376 ButeneContent Mole % 4 3.18 3.18 2.71 CFC Analysis Mn g/mole 33700 32500 3550037000 Mw g/mole 203000 201000 279000 226000 Mw/Mn 6.02 6.18 7.86 6.11Rheology Viscosity at 0.1 I/s Pa · s 69102 50522 124986 70364 Viscosisyat 100 I/s Pa · s 2656 2510 3273 3372 Mechanical Properties TensileProperties Yield Stress Mpa 10.83 12.47 11.71 15.46 Ultim. Stress Mpa30.86 31.65 31.63 25.96 Elongation % 617 704 764 882 Toughness Mpa 102124 133 148 Slope SH Mpa 4.66 4.64 3.92 2.51 2% Sec. Mod. Mpa 216 309244 446 Young's Modulus Mpa 308 354 282 553 Impact Properties Gc +0CkJ/m2 76.4 18.6 35.1 21.5 Ge −20C kJ/m2 14.9 4.2 4.3 3.8 PENT 2.4 MpaMin. >10³ >10³ >10³ 12 Intrinsic Tear g/mil. 226 212 245 201 Haze (0.5mm) % 85.8 70.9 56.6 97.1

TABLE 5 Low Mw Component High Mw Component (Component II) (Component I)Example I₂ mole % density wt % in I₂ mole % density wt % in # dg/10 min1-butene g/cm³ blend g/10 min 1-butene g/cm³ blend Example 13 67.3 0.010.9729 50 0.12 0.76 0.9295 50 Example 14 380 0.01 0.9783 50 0.12 0.760.9295 50 Example 15 380 0.01 0.9783 50 0.13 0.16 0.9378 50 Example 16380 0.01 0.9783 60 0.13 0.16 0.9378 40 Comp. Ex. 8 113 0 0.9753 50 0.150.95 0.9306 50 Comp. Ex. 9 280 0 0.9795 50 0.15 0.95 0.9306 50 Comp. Ex.10 280 0 0.9795 60 0.15 0.95 0.9306 40

TABLE 6 Example Example Example Example Comparative ComparativeComparative Units 13 14 15 16 Ex. 8 Ex. 9 Ex. 10 Melt Flow Properties I₂g/10 min 0.12 0.12 0.13 0.30 0.13 0.18 0.40 I₅ g/10 min 0.51 0.49 0.451.29 0.54 0.74 1.84 I_(21.6) g/10 min 10.9 10.8 11.6 37.0 13.9 20.1 55.5I_(21.6)/I₂ 90.8 89.8 92.0 125.5 109.5 111.4 139.1 Density g/cm3 0.95500.9558 0.9611 0.9647 0.9551 0.9560 0.9603 Impact Properties Charpy +23Ckgfcm/cm2 23.1 18.9 29.5 11.0 17.6 13.5 6.6 Charpy −20C kgfcm/cm2 17.011.4 19.1 7.4 12.5 5.2 2.7 ESCR Bending 80C hr. 1100 >2,000 50 11 170400 20 50C hr. >2,000 >2,000 330 140 1,000 >2,000 360

1. A polymer blend composition, comprising: (a) from 1 to 99% by weightof Component (I) (based on the combined weights of Component (I) andComponent (II)) of an ethylene copolymer, and wherein Component (I) isan ethylene copolymer having the following properties: (1) a density, d(g/cm3), of from 0.870 to 0.980; (2) an M_(w)/M_(n) of from 2.5 to 10,wherein M_(w) and M_(n) are, respectively, a weight average molecularweight and an number average molecular weight, both as measured by gelpermeation chromatography (GPC); (3) when, in cross fractionationchromatography (CFC) of said ethylene copolymer, with respect toextraction at an arbitrary temperature T(° C.) falling within the rangeof between a first temperature, at which a maximum amount of extractionis exhibited and a second temperature, which is the lower temperature ofeither the temperature of 10° C. higher than said first temperature or96° C., the relationship between said arbitrary temperature T(° C.) anda point in molecular weight on a molecular weight distribution profileof a copolymer fraction extracted at said arbitrary temperature T(° C.),at which point in molecular weight, said molecular weight distributionprofile of the copolymer fraction shows a peak having a maximumintensity, is treated by the least squares method to obtain anapproximate straight line within the range of between said firsttemperature and said second temperature; if there is the copolymerfraction, the amount of which is less than 1% by weight on the totalamount, excluding purge, of copolymer fractions extracted attemperatures in the overall range of extraction temperatures in CFC, thecopolymer fraction can be excluded from the calculation for theapproximate straight line; the approximate straight line has a gradientwithin the range defined by the formula (I):−1≦{log Mp(T ¹)−log Mp(T ²)}/(T ¹ −T ²)≦−0.005  (I),  wherein: T¹ and T²are two different arbitrary extraction temperatures T(° C.) within therange of between said first temperature and said second temperature, andMp(T¹) and Mp(T²) are, respectively, molecular weights corresponding toT¹ and T² on said approximate straight line; and (4) the measurement ofsaid ethylene copolymer by CFC shows characteristics, such that the sumof respective amounts of copolymer fractions extracted at temperatures,which are at least 10° C. lower than said first temperature, as definedabove, is 8% by weight or less, based on the total amount, excludingpurge, of copolymer fractions extracted at temperatures in the overallrange of extraction temperatures in CFC; and (b) Component (II), whereinComponent (II) includes a polymer selected from the group consisting of:(a) a second ethylene copolymer of Component (I) of different molecularweight or density, (b) a homogeneous narrow composition distributionethylene interpolymer, and (c) a heterogeneous broad compositiondistribution ethylene interpolymer.
 2. The blend according to claim 1,wherein the ethylene copolymer of Component (I) has an M_(w)/M_(n) ratiothat satisfies the following inequality;1.25 log M _(w)−2.5≦M _(w) /M _(n)≦3.5 log M _(w)−11.0.
 3. The blendaccording to claim 1, wherein the ethylene copolymer of Component (I)has the following property (5) with the properties (1), (2), (3) and(4); (5) within a range in molecular weight of said ethylene copolymerwhich is defined by the formula (II):log(Mt)−log(Mc)≦0.5  (II),  wherein: Mt is a point in molecular weighton a molecular weight distribution profile at which said profile shows apeak having a maximum intensity, and Mc is an arbitrary point inmolecular weight on said molecular weight distribution profile, andwherein said molecular weight distribution profile is obtained, togetherwith a comonomer content distribution profile, by subjecting saidethylene copolymer to gel permeation chromatography/Fouriertransformation infrared spectroscopy (GPC/FT-IR), then an approximatestraight line obtained from said comonomer content distribution profile,by the least squares method, has a gradient within the range defined bythe formula (III):0.0005≦{C(Mc ¹)−C(Mc ²)}/(log Mc ¹−log Mc ²)≦0.05  (III),  wherein: Mc¹and Mc² are two different arbitrary points (Mc) in molecular weight,which satisfy the formula (II), and C(Mc¹) and C(Mc²) are, respectively,comonomer contents corresponding to Mc¹ and Mc² on said approximatestraight line.
 4. The blend according to claim 1, wherein the ethylenecopolymer of Component (I) has an M_(w)/M_(n) ratio of from 3 to
 7. 5.The blend according to claim 1, wherein, with respect to property (3),said approximate straight line, obtained from said molecular weightdistribution profile obtained by CFC of said polymer fraction, has agradient with the range defined by the following formula (IV):−0.1≦{log Mp(T ¹)−log Mp(T ²)}/(T ¹ −T ²)≦0.01  (IV), wherein T¹, T², Mp(T¹) and Mp (T²) are as defined for formula (I) above.
 6. The blendaccording to claim 3, wherein, with respect to property (5), saidapproximate straight line, obtained from said comonomer contentdistribution profile obtained by GPC/FT-IR of said ethylene copolymer,has a gradient within the range defined by the following formula (V):0.001≦{C(Mc ¹)−C(Mc ²)}/(log Mc ¹−log Mc ²)≦0.02  (V), wherein Mc¹, Mc²,C(Mc¹) and C(Mc²) are as defined for formula (III) above.
 7. The blendaccording to claim 1, wherein, with respect to property (4), said sum ofrespective amounts of copolymer fractions, extracted at temperatureswhich are at least 10° C. lower than said first temperature, is 5% byweight or less, based on the total amount, excluding purge, of copolymerfractions extracted at temperatures in the overall range of extractiontemperatures in CFC.
 8. The polymer blend composition of claim 1 having;(1) a density of from 0.870 to 0.980 g/cm³, (2) a melt index, (I₂), offrom 0.0001 to 10,000 g/10 min, (3) an I₁₀/I₂ ratio of from 5 to 100, oran I_(21.6)/I₂ ratio of from 20 to 200, and (4) an M_(w)/M_(n) of from 5to 50; and wherein (a) Component (I) is present in an amount of from 10to 90% by weight, based on the combined weight of Component (I) andComponent (II), and has: i) a density of from 0.870 to 0.980 g/cm³, ii)a melt index (I₂) of from 0.0001 to 10000 g/10 min, iii) an I₁₀/I₂ ratioof from 5 to 30, or an I_(21.6)/I₂ ratio of from 15 to 65, iv) anM_(w)/M_(n) of from 2.5 to 10; and (b) Component (II), forming thebalance and having: i) a density of from 0.915 to 0.985 g/cm³, ii) amelt index (I₂) of from 0.0001 to 10000 g/10 min, and iii) I₁₀/I₂ ratioof from 5 to 40, or an I_(21.6)/I₂ of from 15 to 80, and iv) anM_(w)/M_(n) of from 3 to
 12. 9. The polymer blend composition of claim 1having (1) a density of from 0.915 to 0.975 g/cm³, (2) a melt index,(I₂), of from 0.001 to 5000 g/10 min, (3) an I₁₀/I₂ ratio of from 5 to90, or an I_(21.6)/I₂ ratio of from 30 to 180, and (4) an M_(w)/M_(n) offrom 3 to 45; and wherein (a) Component (I) is present in an amount of25 to 75% by weight, based on the combined weight of Components (I) andComponent (II), and has: i) a density of from 0.890 to 0.965 g/cm³, ii)a melt index, (I₂), of from 0.001 to 5000 g/10 min, iii) an I₁₀/I₂ ratioof from 5 to 28, or an I_(21.6)/I₂ ratio of from 18 to 55, and iv) anM_(w)/M_(n) of from 2.8 to 8; and (b) Component (II), forming thebalance and having i) a density of from 0.935 to 0.983 g/cm³, ii) a meltindex (I₂) of from 0.001 to 5000 g/10 min, iii) an I_(21.6)/I₂ of from20 to 70 or an I₁₀/I₂ of from 5.3 to 35, and iv) an M_(w)/M_(n) of from3.5 to
 10. 10. The polymer blend composition of claim 1 having; 1) adensity of from 0.935 to 0.970 g/cm³, 2) a melt index (I₂), of from 0.01to 3000 g/10 min, 3) an I₁₀/I₂ ratio of from 5 to 80, or an I_(21.6)/I₂ratio of from 40 to 150; and 4) an M_(w)/M_(n) of from 5 to 40; andwherein (a) Component (I) is present in an amount from 35 to 65% byweight, based on the combined weight of Component (I) and Component(II), and has; i) a density of from 0.915 to 0.955 g/cm³, ii) a meltindex (I₂), of from 0.01 to 3000 g/10 min, iii) an I₁₀/I₂ ratio of from5.5 to 25, or an I_(21.6)/I₂ ratio of from 20 to 50; and iv) anM_(w)/M_(n) of from 3 to 7; and (b) Component (II) forming the balanceand having i) a density of from 0.955 to 0.980 g/cm³, ii) a melt index(I₂) of from 0.01 to 3000 g/10 min; iii) an I_(21.6)/I₂ ratio of from 20to 60, or an I₁₀/I₂ ratio of from 5.5 to 30, and iv) an M_(w)/M_(n) offrom 3 to
 9. 11. The polymer blend compositon of claim 1, whereinComponent (II) contains long chain branches.
 12. The polymer blendcomposition of claim 1, wherein Component (I) has a lower density and ahigher molecular weight than Component (II).
 13. A film prepared fromthe composition of claim
 1. 14. A blow-molded article prepared from thecomposition of claim
 1. 15. An injection-molded article prepared fromthe composition of claim
 1. 16. A pipe prepared from the composition ofclaim
 1. 17. A coating material for an electric transmission cableprepared from the composition of claim
 1. 18. A method for preparing thecomposition of claim 1, said method comprising blending Component (I)with Component (II) to form a blend, and wherein at least Component (I)is made using a continuous polymerization process.
 19. A method forpreparing the composition of claim 1, said method comprising, makingeach component separately in different reactors, and subsequentlyblending the components together.